PDF/UA-1 · CLAUSE 7.1
Document is not tagged
The file has no usable logical structure: either the Marked flag is missing, there is no structure tree, or structure elements are detached from their parents.
Why it matters
This is the most severe accessibility failure. Without a structure tree, assistive technology has no reading order, no headings, and no way to describe content. Everything else in PDF/UA depends on this.
How to fix it
- Tag the document at the source: use Word, InDesign, or LaTeX export settings that produce a tagged PDF.
- If you only have the PDF, run Acrobat Pro's Accessibility > Autotag Document, then review the reading order manually.
- Never rely on autotagging alone for tables, forms, or multi-column layouts: check the result in the Tags panel.
WCAG 1.3.1 Info and Relationships (A)
WCAG 1.3.2 Meaningful Sequence (A)
What the standard says
The logical structure of the conforming file shall be described by a structure hierarchy rooted in the StructTreeRoot entry of the document catalog dictionary, as described in ISO 32000-1:2008, 14.7
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"