add info in readme

README.md

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 ---
-license: mit
+language:
+- ru
+license: cc-by-sa-4.0
+pretty_name: Russian Wikipedia quality articles (20261001)
+configs:
+- config_name: articles
+  default: true
+  data_files:
+  - split: corpus
+    path: data/articles.jsonl.gz
+- config_name: categories
+  data_files:
+  - split: corpus
+    path: data/categories.jsonl.gz
 ---
+
+# Russian Wikipedia quality articles — 20261001
+
+A Russian-language corpus of **17,413 Wikipedia articles** with active community
+quality status in the **20261001** Russian Wikipedia dump, accompanied by a
+catalog of **831,556 categories**. Each article includes its title, source
+wikitext, extracted readable text, direct categories, quality status and revision
+links. The category catalog supports inspection of direct membership and parent
+relationships; it is not a curated subject taxonomy.
+
+## Coverage and selection
+
+The corpus is the union of namespace-0 articles in these direct SQL categories:
+
+| Status value | Russian designation | Selection category | Articles |
+| --- | --- | --- | ---: |
+| `recommended` | Добротные статьи | `Википедия:Добротные_статьи_по_алфавиту` | 9,937 |
+| `good` | Хорошие статьи | `Википедия:Хорошие_статьи_по_алфавиту` | 5,264 |
+| `featured` | Избранные статьи | `Википедия:Избранные_статьи_по_алфавиту` | 2,212 |
+
+Redirects and disambiguation pages are excluded. Statuses are stored as lists:
+multiple active statuses are preserved rather than ranked or collapsed. Former
+status categories are retained separately and do not exclude an article that has
+an active status. These are community editorial designations at this snapshot,
+not independent factual checks or current assessments.
+
+All selected articles are retained. There is no thematic filtering, sampling,
+NLP processing, subject-label assignment or research train/test split. There are
+no exact duplicate `wikitext` or `raw_text` values in this snapshot; the selection
+procedure does not remove records because they share text. The `corpus`
+partition is a storage partition, not a research split.
+
+## Loading
+
+Both configurations use compressed JSON Lines and require no dataset script.
+With Hugging Face Datasets:
+
+```python
+from datasets import load_dataset
+
+articles = load_dataset(
+    "TopicNet/RuWiki-Good-2026-V2", "articles", split="corpus"
+)
+categories = load_dataset(
+    "TopicNet/RuWiki-Good-2026-V2", "categories", split="corpus"
+)
+print(len(articles))    # 17413
+print(len(categories))  # 831556
+```
+
+From a downloaded repository, the same files can be loaded directly:
+
+```python
+articles = load_dataset(
+    "json", data_files={"corpus": "data/articles.jsonl.gz"}, split="corpus"
+)
+categories = load_dataset(
+    "json", data_files={"corpus": "data/categories.jsonl.gz"}, split="corpus"
+)
+```
+
+## Article fields
+
+| Field | JSON type | Meaning |
+| --- | --- | --- |
+| `id` | string | Stable page identity, `ruwiki/<page_id>`. |
+| `page_id` | integer | Russian Wikipedia page ID. |
+| `title` | string | Article title with spaces, separate from the text. |
+| `wikitext` | string | XML-decoded revision wikitext. |
+| `raw_text` | string | Readable text extracted from `wikitext`; not rendered HTML. |
+| `wikitext_sha256` | string | SHA-256 of UTF-8 encoded `wikitext`. |
+| `raw_text_sha256` | string | SHA-256 of UTF-8 encoded `raw_text`. |
+| `quality_statuses` | array of strings | Active `recommended`, `good` and/or `featured` statuses from SQL. |
+| `former_quality_categories` | array of strings | Direct former-status category names from SQL; may be empty. |
+| `categories` | array of strings | All direct SQL category names, including maintenance categories. |
+| `wikidata_id` | string or null | Wikidata QID from SQL page properties, when available. |
+| `revision_id` | integer | Content revision ID from XML. |
+| `revision_timestamp` | string | XML revision timestamp in UTC, such as `2026-09-26T22:17:57Z`. |
+| `metadata_revision_id` | integer | SQL page revision ID; may differ from `revision_id`. |
+| `page_url` | string | Page-ID URL for the source page and access to its history. |
+| `revision_url` | string | Permanent URL for the content revision. |
+
+The table describes the stored JSON types. Hugging Face Datasets 5.0.0 infers
+`revision_timestamp` as `timestamp[s]` and `former_quality_categories` as
+`List(null)` for this release, whose former-status lists are empty. Nullable
+scalar fields remain nullable when loaded.
+
+For example, the following is an actual record projected onto a few fields (the
+text and remaining fields are omitted here):
+
+```json
+{
+  "id": "ruwiki/21",
+  "page_id": 21,
+  "title": "Социология",
+  "quality_statuses": ["featured"],
+  "wikidata_id": "Q21201",
+  "revision_id": 155304860,
+  "metadata_revision_id": 155304860,
+  "revision_timestamp": "2026-09-26T22:17:57Z",
+  "page_url": "https://ru.wikipedia.org/?curid=21",
+  "revision_url": "https://ru.wikipedia.org/w/index.php?oldid=155304860"
+}
+```
+
+## Category fields and joins
+
+| Field | JSON type | Meaning |
+| --- | --- | --- |
+| `title` | string | Category name without the category namespace prefix, preserving SQL underscores. |
+| `page_id` | integer or null | Category page ID; null for redlinks. |
+| `wikidata_id` | string or null | Wikidata QID, when available. |
+| `is_hidden` | boolean or null | Hidden-category flag; null for redlinks. |
+| `is_redirect` | boolean or null | Category-page redirect flag; null for redlinks. |
+| `parents` | array of strings | Direct parent category names in the same spelling as `title`. |
+
+The catalog includes all category pages in the SQL snapshot and referenced
+categories without a page (redlinks), rather than only categories used by the
+selected articles. There are **72,676 redlinks**, **2,047,936 parent links** and
+**269,139 direct article-category links**. Redlink records have null page ID,
+flags and QID and an empty parent list. Parent cycles and redirect flags are
+preserved; parent links do not define a tree or validated semantic hierarchy.
+
+Join an article's `categories` entries, or a category's `parents` entries, to
+category `title` exactly, without converting underscores to spaces. Article
+`title` uses spaces and is not the join key. For instance, `Социология` is a direct
+category of article `ruwiki/21`. The following complete category record illustrates
+the stored format:
+
+```json
+{
+  "is_hidden": false,
+  "is_redirect": false,
+  "page_id": 3042229,
+  "parents": [
+    "Википедия:Категории_с_основной_статьёй_из_Викиданных",
+    "Категории_музыкальных_коллективов_США"
+  ],
+  "title": "(hed)_P.E.",
+  "wikidata_id": "Q7573257"
+}
+```
+
+## Sources and revision semantics
+
+The source is the [Russian Wikipedia 20261001 dump](https://dumps.wikimedia.org/ruwiki/20261001/).
+The exact source files are listed below with their SHA-256 digests. Dump mirrors
+may later remove this dated snapshot; the filenames and digests identify the
+inputs independently of their continued availability.
+
+| File | SHA-256 |
+| --- | --- |
+| `ruwiki-20261001-page.sql.gz` | `24250cca6122fff02896a1ced0a85b7afa4d6be00fa119c169a5eeef3fbe5830` |
+| `ruwiki-20261001-page_props.sql.gz` | `fc9d5aeaf3487d932b82d18a16bc96f0e4e4702e1149cbbdc482eb509f6deb60` |
+| `ruwiki-20261001-categorylinks.sql.gz` | `1ecb32ffaff28a120b6a8f4297d4b228b65c49beb593eae022b5811ae41512e1` |
+| `ruwiki-20261001-linktarget.sql.gz` | `bc1f24b7b8eb06298cbe70fdfb010ec023586d05bd2d3403ba2370091e1edc4a` |
+| `ruwiki-20261001-pages-articles-multistream.xml.bz2` | `c22b6441176d2bc572ed6883abc6292fe168efca211f6cdd61d8772a78492a1b` |
+| `ruwiki-20261001-pages-articles-multistream-index.txt.bz2` | `17c6a4cebb90ecb2b0f881e04aa3b49356bd6ee6add802a7201b9ca1a9b093e3` |
+
+SQL provides selection, titles, page properties and category relationships. XML
+provides article content, `revision_id` and `revision_timestamp`. **11 articles**
+have differing SQL and XML revision IDs; the metadata and content should not be
+assumed to describe one atomic revision. Use `revision_url` to identify the exact
+text revision, and retain both IDs when recording provenance. Live pages and
+categories can differ from this snapshot.
+
+Readable extraction uses `mwparserfromhell` 0.7.2 and deterministic markup cleanup.
+It does not render Wikipedia or expand templates fully. Templates, infoboxes,
+tables, references, captions, formulae and formatting may be removed or simplified;
+fragments of markup or awkward text may remain. `wikitext` is retained so readers
+can inspect these losses or apply a different extraction procedure. Neither
+`raw_text` nor the category metadata is a manually corrected annotation.
+
+## Attribution, license and use
+
+Article text and wikitext are attributed to **Russian Wikipedia contributors**
+and distributed under [Creative Commons Attribution-ShareAlike 4.0](https://creativecommons.org/licenses/by-sa/4.0/).
+Each record's `revision_url` identifies the revision used; `page_url` provides
+access to the page and its edit history for contributor attribution. Follow
+attribution and share-alike requirements when redistributing text or adaptations,
+identify your changes, and preserve appropriate source links. Wikipedia can
+contain quotations or other third-party material with additional terms. Wikidata
+identifiers refer to [Wikidata](https://www.wikidata.org/wiki/Wikidata:Licensing),
+whose structured data is available under CC0; their presence does not change the
+license of the article text. Images and other media binaries are not included.
+
+Potential uses include Russian text analysis, inspection of markup extraction and
+research on Wikipedia editorial metadata or category relationships. This is a
+small, editorially selected portion of Russian Wikipedia, not a representative
+sample of Russian writing or an evenly balanced subject collection. Quality
+status does not guarantee accuracy, neutrality, completeness or suitability for
+any downstream application. Articles can contain sensitive, biased, outdated or
+offensive material. Any subject labels, deduplication policy, preprocessing and
+research splits needed for a downstream study must be specified separately.
+
+## Published file identity
+
+| File | Compressed bytes | SHA-256 |
+| --- | ---: | --- |
+| `data/articles.jsonl.gz` | 409,970,311 | `c51f9b6bee4c85f25ffb861060f52490a9276bae289d2aa2db7e0d10e2dda950` |
+| `data/categories.jsonl.gz` | 22,459,573 | `d07ab1e6c07da28cc162d786853a73c54e300289e21bcc6667c4072158abdf8f` |