Every ePub3 created by DPS is accompanied by an ACE Report, which validates the file according to current WCAG standards. The report is built by the "ACE checker," a tool developed by the DAISY Consortium to evaluate the accessibility of EPUB files.
It is important to note, however, that ACE is only a quick check. The report does not cover or validate all WCAG qualities.
For full validation, a file must be certified as compliant.
See here for more on that subject.The Value of ACE
1. Automated Checks: ACE automates the
process of finding common issues that might be easily overlooked.
2. Currency: EPUB Accessibility
specifications/WCAG guidelines change frequently; the report is aligned with those current as of the report date.
3. Detail: The report points out issues and offering guidance on how to resolve them.