What this test checks
This test checks whether elements with figure semantics are tagged using the /Figure structure type rather than a different structural tag. Elements without explicit figure semantics are not evaluated.
Why this maybe a barrier
If elements representing meaningful graphical content are not properly tagged as <Figure> element, it can confuse assistive technologies when processing such elements and they may mistakenly process them as artifacts or text thereby reducing the comprehension of the document or causing errors.
In general, it is important to mark elements correctly in the PDF structure tree for semantic correctness and comprehension.
NOTE: This test skips Figure elements themselves.
WCAG 2.2 Success Criterion
N.A (PDF/UA-only check).
PDF/UA Principle
Section 7.3: Graphics— "Graphics objects, other than text objects, shall be tagged with a Figure tag as described in ISO 32000-1:2008, 14.8.4.5, Table 340."
For implementation, it uses Matterhorn protocol checkpoint namely 13-001:
13-001 — Graphics objects other than text objects and artifacts are not tagged with a <Figure> tag.