PDF/UA-1 · CLAUSE 7.21.5
Font is not embedded or is inconsistently encoded
A font used for rendering is not embedded, is missing glyphs, or has encoding tables that do not let a reader map character codes to glyphs reliably.
Why it matters
Text may render with substituted glyphs, and text extraction can produce wrong characters, so both sighted readers and screen reader users can get corrupted text.
How to fix it
- Embed all fonts, including subsets, when exporting the PDF.
- Avoid fonts with broken or missing cmap tables; substitute a well-formed font in the source document.
- Check the export preset: 'optimised for size' presets often drop font embedding.
What the standard says
For every font embedded in a conforming file and used for rendering, the glyph width information in the font dictionary and in the embedded font program shall be consistent
Check your own PDF
Validate a file against PDF/UA-1 and see whether this rule fails in your document.
curl -sS -X POST "https://api.ua1.dev/api/validate?format=compact&profile=ua1" \ -F "file=@document.pdf"