Updated November 2018

Accessibility metadata for digital books is drawn from four main sources, which are cross-walked here.

EPUB, Dublin Core, and ONIX

The EPUB Accessibility 1.0 specification defines the following metadata terms, some of which are also defined in ONIX:

EPUB Dublin Core ONIX
certifiedBy List: 196; Code: 98: Trusted Intermediary contact
certifierReport List: 196; Code: 94: Compliance web page for detailed accessibility information or, if a publisher is self-certifying, Code: 96: Publisher’s web page for detailed accessibility information
dcterms:conformsTo WCAG-A conformsTo WCAG-A List: 196; Code: 02: Accessibility Specification 1.0 A
dcterms:conformsTo WCAG-AA conformsTo WCAG-AA List: 196; Code: 03: Accessibility Specification 1.0 AA and ONIX includes a large group of accessibility metadata properties which are referenced in the EPUB Accessibility 1.0 specification, some of which are also defined in ONIX: ONIX
accessibilityFeature (vocabulary list follows) List 196 (specific codes follow)
    alternativeText List: 196; Code: 14: Short alternative descriptions
    ChemML List: 196; Code: 18: Accessible chem content
    index List: 196; Code: 12: Index navigation
    longDescription List: 196; Code: 15: Full alternative descriptions; 16: Visualised data also available as non-graphical data
    MathML List: 196; Code: 17: Accessible math content
    printPageNumbers List: 196; Code: 19: Print-equivalent page numbering
    readingOrder List: 196; Code: 13: Reading order
    sychronizedAudioText List: 196; Code: 20: Synchronised pre-recorded audio
    tableOfContents List: 196; Code: 11: Table of contents navigation
    ttsMarkup List: 196; Code: 21: Text-to-speech hinting provided; 22: Language tagging provided
accessibilityHazard (vocabulary list follows)
accessibilityAPI (vocabulary list follows)
accessibilityControl (vocabulary list follows)
accessMode (vocabulary list follows)
    chartOnVisual List: 81; Code 19: Figures, Diagrams, Charts
    diagramOnVisual List: 81; Code 19: Figures, Diagrams, Charts
    textual List: 81; Code: 10 combined with List: 196; Code: 10 means all text is actual text. List: 81; Code: 10 on its own (without List: 196; Code: 10) admits the possibility that the ‘text’ is inaccessible because it is an image of text.
    visual List: 81; Code: 07: Still images / graphics or Code: 18: Photographs or Code: 19: Figures, diagrams, charts, graphs or Code: 12: Maps and/or other cartographic content
accessModeSufficient (vocabulary list follows)
accessibilitySummary List: 196; Code: 00: Accessibility Summary
    Human-readable text

For comments or discussion, enter the discussion on our Discuss page.