| --- |
| pretty_name: "File format magic numbers" |
| license: other |
| license_name: source-terms-cited |
| license_link: https://referencesource.org/file-format-signatures/ |
| language: |
| - en |
| tags: |
| - reference-data |
| - provenance |
| - referencesource-org |
| configs: |
| - config_name: default |
| data_files: |
| - split: train |
| path: data/records.jsonl |
| --- |
| # File format magic numbers |
|
|
| **Canonical, always-current version: https://referencesource.org/file-format-signatures/** |
| Machine-readable: https://referencesource.org/file-format-signatures/data.json — this mirror is a point-in-time copy. |
|
|
| - **Last verified:** 2026-09-22 |
| - **Stale after:** 2027-09-22 (past this date, prefer the canonical copy — |
| it re-verifies on a cadence this snapshot does not) |
| - **Records:** 337 |
|
|
| The leading bytes (magic number / file signature) that identify a file format, with its usual extension. Answers 'what actually is this file' when the extension is wrong or missing. Covers what Wikipedia's List of file signatures publishes — a broad cross-section, not every format that exists. |
|
|
| ## Provenance — what every record carries |
|
|
| Every record carries `source` (the URL the value was read from) and |
| `source_quote` (a verbatim quote from that page stating it). A value you |
| cannot check against its page is indistinguishable from an invented one; |
| these can all be checked. Each record is also individually addressable on |
| the canonical site at its `url`. |
|
|
| ## Licence position |
|
|
| CC BY-SA 4.0 (source: Wikipedia) |
|
|
| Facts are not copyrightable; what this dataset takes from each source is a |
| fact plus a short attributed quote linking back to the page that states it. |
|
|
| ## Sources |
|
|
| - https://en.wikipedia.org/wiki/List_of_file_signatures |
| |
| ## Fields |
| |
| See any record in `data/records.jsonl` — field names are self-describing, |
| and the canonical page for each record renders them with labels: |
| https://referencesource.org/file-format-signatures/ |
| |
