ISO IEC 23761 pdf – Digital publishing — EPUB accessibility — Conformance and discoverability requirements for EPUB publications
Authors of such EPUB publications are encouraged to create content in conformance with the accessibility and discoverability requirements of this document. Upgrading to the latest version of EPUB to get access to the most advanced accessibility features and techniques is also encouraged. 6 Discoverability 6.1 General Unlike web pages, EPUB publications are designed to be distributed through many channels for personal consumption — a model that has made EPUB a successful format for ebooks and other types of digital publications. A consequence of this model, however, is that specific details about the accessibility of a publication need to travel with it. An online bookstore aggregating content from publishers and authors, for example, does not know the production quality that went into each submission unless the publisher informs them through metadata. Ensuring that the accessible qualities of an EPUB publication can be discovered by any interested party is therefore a primary concern. Users need to be able to gauge the usability of an EPUB publication when they purchase, borrow or otherwise obtain it, a determination that requires knowing the affordances made to meet the accessibility requirements.
Similarly, content that does not meet the accessibility requirements of this document does not necessarily fail to meet the needs of individual users. Only through the provision of rich metadata can a user decide if the content is suitable for them. 6.2 Package metadata All EPUB publications shall include accessibility metadata in the package document that exposes their accessible properties, regardless of whether the publications also meet the accessibility ( Clause 7 ) or optimization (Clause 8) requirements. EPUB publications shall include the following accessibility metadata:
— Access modes
— a human sensory perceptual system or cognitive faculty necessary to process or perceive the content (e.g. textual, visual, auditory, tactile). — Accessibility features
— features and adaptations that contribute to the overall accessibility of the content (e.g. alternative text, extended descriptions, captions).
— Accessibility hazards
— any potential hazards that the content presents (e.g. flashing, motion simulation, sound). — Accessibility summary
— a human-readable summary of the overall accessibility, which includes a description of any known deficiencies (e.g. lack of extended descriptions, specific hazards). EPUB publications should include the following accessibility metadata:
— Sufficient access modes — a set of one or more access modes sufficient to consume the content without significant loss of information. An EPUB publication can have more than one set of sufficient access modes for its consumption depending on the types of content it includes (i.e. unlike access modes, this property takes into account any affordances for content that is not broadly accessible, such as the inclusion of transcripts for audio content). EPUB publications may include the following accessibility metadata:
— Accessibility application programming interfaces (APIs)
— to indicate the resource is compatible with the specified accessibility API. This property is typically only used to indicate that the use of scripting in an EPUB publication follows Accessible Rich Internet Applications (WAI-ARIA) 1.1authoring practices, as compatibility with operating system accessibility APIs is a concern for reading systems.
— Accessibility controls — input methods that can be used to access the content (e.g. keyboard, mouse). Authors may include additional accessibility metadata not specified in this subclause. NOTE See Discovery Metadata Techniques in EPUB Accessibility Techniques for more information on these properties and how to include them in different versions of EPUB. See also DIST-002: Include accessibility metadata in distribution records in EPUB Accessibility Techniques for more information on including accessibility metadata in other formats.
6.3 Linked metadata records Accessibility metadata can also be included in linked records (see ISO/IEC 23736-2) (i.e. metadata records referenced from link elements), but the inclusion of such metadata solely in a linked record does not satisfy the discoverability requirements of this document.
7 Accessible publications