Accesibilidad de EPUB

El pasado 25 de mayo de 2023 se publicó al mismo tiempo EPUB 3.3 y EPUB Accessibility 1.1, que define los requisitos de accesibilidad de EPUB.

En EPUB Accessibility 1.1 podemos leer:

The primary source for producing accessible web content is the W3C's Web Content Accessibility Guidelines (WCAG) [wcag2], which establish benchmarks for accessible content. WCAG defines four high-level content principles — that content be perceivable, operable, understandable, and robust. These principles are also central to creating accessible EPUB publications, so it is no surprise that this specification builds on the extensive work done in WCAG.

Y después en 3.2 Relationship to WCAG dice:

WCAG [wcag2] and its associated techniques provide extensive coverage of issues and solutions for web content accessibility, covering everything from multimedia to interactive content to structured markup and more. They represent the foundation that this specification builds upon.

This specification does not repeat the requirements or techniques introduced in those documents, as it risks breaking compatibility between the two standards (e.g., putting guidance out of sync, or in conflict). At the same time, although this specification does not call out those requirements, it does not diminish their importance in creating EPUB publications that are accessible.

This specification instead defines how to apply WCAG to an EPUB publication — which is a collection of web documents as opposed to a single page — and adds an additional set of requirements. These requirements are no more or less important than those covered in WCAG; they are simply necessary to follow for EPUB publications. (Each requirement explains its relationship to WCAG in its respective section.)

The same is true of the techniques in the EPUB Accessibility Techniques document [epub-a11y-tech-11]. It provides coverage of techniques that are unique to EPUB publications, or that need clarification in the context of an EPUB publication. It does not mean that the rest of the WCAG techniques are not applicable.

As a result, although EPUB creators can read this section without deep knowledge of WCAG conformance, to implement the accessibility requirements of this specification requires an understanding of WCAG.

Because this specification adds requirements that are not a part of WCAG, an EPUB publication can conform to WCAG without conforming to this specification.

En EPUB 3.3 becomes a W3C Recommendation podemos leer:

Accessibility of EPUB publications was an essential part of the group’s activity. As a result, the EPUB Accessibility specification has been updated and, for the first time in the history of EPUB, is now an integral part of the EPUB Standard. Furthermore, the EPUB Accessibility specification is compatible with the European Accessibility Act whose influence will be significant on Digital Publishing in the years to come.