What does the Wikimedia Commons imageinfo extmetadata return for licence and credit, and how does the extension documentation qualify those fields?

Wikimedia's CommonsMetadata extension describes its extmetadata fields as a temporary solution that outputs parsed HTML and warns that licence values are unreliable for multi-licensed images (with License a best guess and LicenseShortName probably more reliable); a sampled file (Hopetoun_falls.jpg) reports CC BY-SA 3.0 in the licence fields while its categories include GFDL and 'License migration redundant', i.e. a multi-licence case the single licence field does not show. Curator qualifications: Whether the file is dual-licensed GFDL/CC BY-SA is inferred from categories; the file description page was not read. API version-history details (S7, E8) not reinspected; live API response may change. Documentation and one API response; no media downloaded. Rights/verification notes are shown as limitations (L00 0019/ADR-0011): they restrict reuse of the cited material or record what was not verified; they are not cleared by this summary. Limitations: One sampled file. [component_reuse_restriction] For Commons media, read the file page licence templates, not only extmetadata. Evidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.

{
  "citations": [
    {
      "url": "https://www.mediawiki.org/w/index.php?title=Extension:CommonsMetadata&action=raw",
      "note": "mediawiki.org Extension:CommonsMetadata (raw), lines 32, 52, 151, 164; commons.wikimedia.org api.php imageinfo extmetadata for File:Hopetoun_falls.jpg (fetched 2026-10-22)"
    },
    {
      "url": "https://commons.wikimedia.org/w/api.php?action=query&titles=File:Hopetoun_falls.jpg&prop=imageinfo&iiprop=extmetadata|url&format=json&formatversion=2",
      "note": "mediawiki.org Extension:CommonsMetadata (raw), lines 32, 52, 151, 164; commons.wikimedia.org api.php imageinfo extmetadata for File:Hopetoun_falls.jpg (fetched 2026-10-22)"
    },
    {
      "url": "https://www.mediawiki.org/w/index.php?title=API:Imageinfo&action=raw",
      "note": "mediawiki.org Extension:CommonsMetadata (raw), lines 32, 52, 151, 164; commons.wikimedia.org api.php imageinfo extmetadata for File:Hopetoun_falls.jpg (fetched 2026-10-22)"
    }
  ]
}