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 theaccessibility and discoverability requirements of this document. Upgrading to the latest version ofEPUB to get access to the most advanced accessibility features and techniques is also encouraged.
6Discoverability
6.1General
Unlike web pages,EPUB publications are designed to be distributed through many channels for personalconsumption— a model that has made EPUB a successful format for ebooks and other types of digitalpublications. A consequence of this model, however, is that specific details about the accessibility of apublication need to travel with it.
An online bookstore aggregating content from publishers and authors, for example,does not knowthe production quality that went into each submission unless the publisher informs them throughmetadata.
Ensuring that the accessible qualities of an EPUB publication can be discovered by any interested partyis therefore a primary concern.Users need to be able to gauge the usability of an EPUB publication whenthey purchase, borrow or otherwise obtain it, a determination that requires knowing the affordancesmade to meet the accessibility requirements.
Similarly，content that does not meet the accessibility requirements of this document does notnecessarily 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 theiraccessible properties,regardless of whether the publications also meet the accessibility (Clause 7) oroptimization (Clause 8) requirements.
EPUB publications shall include the following accessibility metadata:
Access modes — a human sensory perceptual system or cognitive faculty necessary to process orperceive the content (e.g.textual, visual, auditory, tactile).
Accessibility features —features and adaptations that contribute to the overall accessibility of thecontent (e.g. alternative text, extended descriptions, captions).
Accessibility hazards – any potential hazards that the content presents (e.g. flashing motionsimulation, sound).
Accessibility summary — a human-readable summary of the overall accessibility, which includes adescription 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 contentwithout significant loss of information.An EPUB publication can have more than one set of sufficientaccess modes for its consumption depending on the types of content it includes (i.e.unlike accessmodes, 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 (APls) — to indicate the resource is compatiblewith the specified accessibility API.This property is typically only used to indicate that the use ofscripting in an EPUB publication follows Accessible Rich Internet Applications (WAI-ARIA) 1.1[3 authoring practices, as compatibility with operating system accessibility APls is a concern forreading systems.
一 Accessibility controls— input methods that can be used to accessthe content(e.g.keyboard,mouse).Authors may include additional accessibility metadata not specified in this subclause.
NOTE See Discovery Metadata Techniques in EPUB Accessibility Techniques7 for more information onthese properties and how to include them in different versions of EPUB.See also DIST-002: Include accessibilitymetadata in distribution records in EPUB Accessibility Techniques7 for more information on includingaccessibility metadata in other formats.
6.3 Linked metadata records
Accessibility metadata can also be included in linked records (see lSo/IEC 23736-2) (i.e. metadatarecords referenced from link elements), but the inclusion of such metadata solely in a linked recorddoes not satisfy the discoverability requirements of this document.
7 Accessible publications
7.1General
EPUB is built on the Open Web Platform, with HTML,CSS,JavaScript and SVG, the core technologiesused for content authoring.The use of these technologies means that EPUB publications can beauthored with a high degree of accessibility simply through the proper application of established webaccessibility techniques.
The primary source for the production of accessible web content is the W3C Web Content AccessibilityGuidelines (WcAG) 2.0 (ISO/IEC 40500).This document leverages the extensive work done in WCAG 2.0to establish benchmarks for accessible content, and the same four high-level content principles 一perceivable, operable, understandable and robust — are central to creating EPUB publications that areaccessible.
This clause defines how to apply the conformance criteria defined in WCAG 2.0 and addresses qualitiesunique to EPUB publications.
EPUB publications authored to comply with the requirements in this clause will have a high degree ofaccessibility for users with a wide variety of reading needs and preferences.
7.2 Relationship to wcAG
WCAG 2.0 (ISO/IEC 40500) and its associated techniques (WCAG 2.0 techniques) provide extensivecoverage of issues and solutions for web content accessibility — from tables to embedded multimediato rich semantics. They represent the foundation that this document builds upon.