{"schema":"record/v1","id":"art_01M5MV8W3WK17E4CAYGTM93F9M","type":"article","revision":1,"etag":"\"r1.s0\"","title":"What language, text-direction and Unicode-mapping information can a PDF carry, and what do PDF/A and PDF/UA validators actually check about it?","summary":"ISO 32000-1 (PDF 1.7) lets a PDF set a default language in the document catalogue (Lang), override it on structure elements and on marked-content Span sequences, and even inside text strings via a language escape; the empty string means unknown, and tags are cited as RFC 3066 language tags (RFC 5646 says RFC-3066-valid tags remain valid). Direction is a separate Tagged PDF layout attribute (WritingMode). veraPDF's machine-readable rules show that PDF/A-2 Level A checks the Lang string syntactically (regex), PDF/UA-2 requires a non-empty catalogue Lang, and PDF/A-2 Level A/U requires a Unicode map for every font. None of the inspected rules checks that the declared language matches the text or the font's coverage.","status":"active","body":{"text":"ISO 32000-1 (PDF 1.7) lets a PDF set a default language in the document catalogue (Lang), override it on structure elements and on marked-content Span sequences, and even inside text strings via a language escape; the empty string means unknown, and tags are cited as RFC 3066 language tags (RFC 5646 says RFC-3066-valid tags remain valid). Direction is a separate Tagged PDF layout attribute (WritingMode). veraPDF's machine-readable rules show that PDF/A-2 Level A checks the Lang string syntactically (regex), PDF/UA-2 requires a non-empty catalogue Lang, and PDF/A-2 Level A/U requires a Unicode map for every font. None of the inspected rules checks that the declared language matches the text or the font's coverage.\n\nCurator qualifications: PDF Lang at catalogue, structure element and marked-content Span; inheritance; empty = unknown; RFC 3066 cited. veraPDF rule texts not located among decoded copies (producer read them from the repo).\n\nEvidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.","citations":[{"url":"https://opensource.adobe.com/dc-acrobat-sdk-docs/pdfstandards/PDF32000_2008.pdf","note":"ISO 32000-1 14.9.2.2 (layout text L40516-L40517; uncompressed sha a6b31f4f matches producer list)"},{"url":"https://www.rfc-editor.org/rfc/rfc5646.txt","note":"ISO 32000-1 14.9.2.2 (layout text L40516-L40517; uncompressed sha a6b31f4f matches producer list)"},{"url":"https://github.com/veraPDF/veraPDF-validation-profiles/tree/b76c28ff0d8809c30c4d0e64dc6c393f3c9019dc","note":"ISO 32000-1 14.9.2.2 (layout text L40516-L40517; uncompressed sha a6b31f4f matches producer list)"}]},"categories":["T17","T20"],"tags":[],"language":"en","visibility":"public","moderation":{"state":"visible","reason":null},"evidence":{"inspection":"source_inspected","execution":"not_run","review":"unreviewed","review_revision":null,"claims":[{"url":"https://opensource.adobe.com/dc-acrobat-sdk-docs/pdfstandards/PDF32000_2008.pdf","claim":"ISO 32000-1 (PDF 1.7) lets a PDF set a default language in the document catalogue (Lang), override it on structure elements and on marked-content Span sequences, and even inside text strings via a language escape; the empty string means unknown, and tags are cited as RFC 3066 language tags (RFC 5646 says RFC-3066-valid tags remain valid). 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Direction is a separate Tagged PDF layout attribute (WritingMode). veraPDF's machine-readable rules show that PDF/A-2 Level A checks the Lang string syntactically (regex), PDF/UA-2 requires a non-empty catalogue Lang, and PDF/A-2 Level A/U requires a Unicode map for every font. None of the inspected rules checks that the declared language matches the text or the font's coverage.\n\nCurator qualifications: PDF Lang at catalogue, structure element and marked-content Span; inheritance; empty = unknown; RFC 3066 cited. veraPDF rule texts not located among decoded copies (producer read them from the repo).\n\nEvidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.","citations":[{"url":"https://opensource.adobe.com/dc-acrobat-sdk-docs/pdfstandards/PDF32000_2008.pdf","note":"ISO 32000-1 14.9.2.2 (layout text L40516-L40517; uncompressed sha a6b31f4f matches producer list)"},{"url":"https://www.rfc-editor.org/rfc/rfc5646.txt","note":"ISO 32000-1 14.9.2.2 (layout text L40516-L40517; uncompressed sha a6b31f4f matches producer list)"},{"url":"https://github.com/veraPDF/veraPDF-validation-profiles/tree/b76c28ff0d8809c30c4d0e64dc6c393f3c9019dc","note":"ISO 32000-1 14.9.2.2 (layout text L40516-L40517; uncompressed sha a6b31f4f matches producer list)"}]},"tags":[],"type":"article","links":[],"title":"What language, text-direction and Unicode-mapping information can a PDF carry, and what do PDF/A and PDF/UA validators actually check about it?","rights":[{"notes":"Applies to this original summary only, not to the cited sources.","hosting":"permitted","component":"documentation","license_id":null,"modification":"unknown","evidence_urls":[],"model_training":"unknown","redistribution":"permitted"}],"summary":"ISO 32000-1 (PDF 1.7) lets a PDF set a default language in the document catalogue (Lang), override it on structure elements and on marked-content Span sequences, and even inside text strings via a language escape; the empty string means unknown, and tags are cited as RFC 3066 language tags (RFC 5646 says RFC-3066-valid tags remain valid). 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Direction is a separate Tagged PDF layout attribute (WritingMode). veraPDF's machine-readable rules show that PDF/A-2 Level A checks the Lang string syntactically (regex), PDF/UA-2 requires a non-empty catalogue Lang, and PDF/A-2 Level A/U requires a Unicode map for every font. None of the inspected rules checks that the declared language matches the text or the font's coverage.","locator":"ISO 32000-1 14.9.2.2 (layout text L40516-L40517; uncompressed sha a6b31f4f matches producer list)","classification":"sourced_fact"}],"review":"unreviewed","execution":"not_run","inspection":"source_inspected","execution_record_ids":[]},"language":"en","categories":["T17","T20"],"extensions":{"curation/v1":{"curator":"CURATOR-A-20261021","revision":1,"topic_ids":["CAT:T17.15"],"confidence":"Not stated; see limitations.","limitations":["Source pin hashes are native catalogue descriptor hashes, not upstream byte hashes. 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