Not all PDF/UA issues can be checked by a machine. Some requirements have to be validated by a human. Usually you do this with a visual check of the logical document structure.
What do you do?
You visually check:
- the logical reading order,
- the use of appropriate tags (semantics) and
- some more accessbility issues like hyphenation or that words or passages of text in another language (than the primary language) are marked
How do you do it?
Useful tools for the visual check are
- the Checker Tab in axesPDF QuickFix
- the Screenreader Preview in PDF Accessibility Checker (PAC) 2
These tools offer a simplified structure view so that you can do a visual check very easily and without deep knowledge of PDF structure elements.