What this test checks
This test checks the consistency of non-standard structure elements if any in the PDF document against its RoleMap dictionary.
Why this maybe a barrier
A PDF RoleMap dictionary is a standard data structure that connects custom structure types in a PDF document to standard structure types, ensuring that their intended roles are consistent across different PDF processors. This helps maintain the logical structure and accessibility of PDF documents.
If custom structure types are defined but not mapped to the standard types, assistive technologies cannot understand their semantic meaning. Screen readers rely on standardized tags to interpret document structure. Unmapped custom tags break this chain, causing reading order errors, missing headings, incorrect list navigation, and unpredictable accessibility behavior.
WCAG 2.2 Success Criterion
N.A (PDF/UA-only check).
PDF/UA Principle
Section 7.1: General — "Non-standard structure types are permitted. However, they shall be mapped to the nearest functionally equivalent standard type, as defined in ISO 32000-1:2008, 14.8.4, in the role map dictionary of the structure tree root. This mapping may be indirect; within the role map a non-standard type can map directly to another non-standard type, but eventually the mapping shall terminate at a standard type".
For implementation, it uses the following Matterhorn protocol, checkpoints namely,
- 02-001 — One or more non-standard tag's mapping does not terminate with a standard type.
- 02-003 — A circular mapping exists.
- 02-004 — One or more standard types are remapped.