UA1 Validator / PDF/UA-1 rules / 7.20-1

PDF/UA-1 · CLAUSE 7.20

Form XObject content is not properly structured

The file uses reference XObjects, which PDF/UA forbids, or the content inside a Form XObject is not incorporated into the structure tree.

Rule 7.20-1 ISO 14289-1 Object: PDXForm

Why it matters

Content drawn inside these objects is invisible to assistive technology even though it is visible on the page.

How to fix it

  • Remove reference XObjects and embed the content directly.
  • Tag the content inside Form XObjects so it appears in the structure tree.
  • Re-export from the source application: this class of problem is rarely worth fixing by hand.
WCAG 1.3.1 Info and Relationships (A)

What the standard says

A conforming file shall not contain any reference XObjects

Check your own PDF

Validate a file against PDF/UA-1 and see whether this rule fails in your document.

Open the validator Automate in CI 
curl -sS -X POST "https://api.ua1.dev/api/validate?format=compact&profile=ua1" \
  -F "file=@document.pdf"