Update November 09, 2021
This Project is no longer maintained here. This project’s work has been moved to the W3C and has been taken up in a Community Group. For more information please visit the new Accessibility Discoverability Vocabulary For Schema.org Community Group.
Here is a link to the updated Crosswalk between metadata formats.
To review or report issues with the Schema.org Accessibility Properties for Discoverability Vocabulary, please refer to the vocabulary’s GitHub issue tracker.
Original (Outdated)
Updated May 2019
Accessibility metadata for digital books is drawn from three main sources, which are cross-walked here.
EPUB and ONIX
The EPUB Accessibility 1.0 specification defines the following metadata terms, some of which are also defined in ONIX. Note that the conformsTo term used in EPUB is drawn from Dublin Core.
| EPUB | ONIX |
|---|---|
| certifiedBy | – |
| 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 |
| certifierCredential | – |
link rel="dcterms:conformsTo" href="http://www.idpf.org/epub/a11y/accessibility-20170105.html#wcag-a" |
List: 196; Code: 02: EPUB Accessibility Specification 1.0 A |
link rel="dcterms:conformsTo" href="http://www.idpf.org/epub/a11y/accessibility-20170105.html#wcag-aa" |
List: 196; Code: 03: EPUB Accessibility Specification 1.0 AA |
Schema.org and ONIX
Schema.org 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:
| schema.org | ONIX |
|---|---|
| accessibilityFeature (vocabulary list follows) | List 196 (specific codes follow) |
| alternativeText | List: 196; Code: 14: Short alternative descriptions |
| annotations | – |
| audioDescription | – |
| bookmarks | N/A (Reading system feature) |
| braille | – |
| captions | – |
| ChemML | List: 196; Code: 18: Accessible chem content |
| describedMath | – |
| displayTransformability | – |
| highContrastAudio | – |
| highContrastDisplay | – |
| index | List: 196; Code: 12: Index navigation |
| largePrint | – |
| latex | – |
| 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 |
| none | – |
| printPageNumbers | List: 196; Code: 19: Print-equivalent page numbering |
| readingOrder | List: 196; Code: 13: Reading order |
| rubyAnnotations | – |
| signLanguage | – |
| structuralNavigation | – |
| sychronizedAudioText | List: 196; Code: 20: Synchronised pre-recorded audio |
| tableOfContents | List: 196; Code: 11: Table of contents navigation |
| taggedPDF | – |
| tactileGraphic | – |
| tactileObject | – |
| timingControl | – |
| transcript | – |
| ttsMarkup | List: 196; Code: 21: Text-to-speech hinting provided; 22: Language tagging provided |
| unlocked | – |
| – | List: 196; Code 22: Language tagging provided – helps with TTS in multi-lingual content |
| – | List: 196; Code 24: Dyslexia readability |
| – | List: 196; Code 09: Inaccessible |
| – | List: 196; Code 10: No reading system accessibility options disabled |
| accessibilityHazard (vocabulary list follows) | – |
| flashing | – |
| noFlashingHazard | – |
| motionSimulation | – |
| noMotionSimulationHazard | – |
| sound | – |
| noSoundHazard | – |
| unknown | – |
| accessibilityAPI (vocabulary list follows) | – |
| AndroidAccessibility | – |
| ARIA | – |
| ATK | – |
| AT-SPI | – |
| BlackberryAccessibility | – |
| iAccessible2 | – |
| iOSAccessibility | – |
| JavaAccessibility | – |
| MacOSXAccessibility | – |
| MSAA | – |
| UIAutomation | – |
| accessibilityControl (vocabulary list follows) | – |
| fullKeyboardControl | – |
| fullMouseControl | – |
| fullSwitchControl | – |
| fullTouchControl | – |
| fullVideoControl | – |
| fullVoiceControl | – |
| accessMode (vocabulary list follows) | – |
| auditory | – |
| chartOnVisual | List: 81; Code 19: Figures, Diagrams, Charts |
| chemOnVisual | – |
| colorDependent | – |
| diagramOnVisual | List: 81; Code 19: Figures, Diagrams, Charts |
| mathOnVisual | – |
| musicOnVisual | – |
| tactile | – |
| textOnVisual | – |
| textual | List: 81; Code: 10 combined with List: 196; Code: 10 means all text is actual text. Note that 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) | ONIX crosswalks are for instances where accessModeSufficient includes this vocabulary entry alone; combinations may occur but are more difficult to crosswalk |
| auditory | List: 81; Code:01 |
| tactile | – |
| textual | List: 81; Code: 10 combined with List: 196; Code: 10 means all text is actual text. Note that 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 | – |
| accessibilitySummary | List: 196; Code: 00: Accessibility Summary |
| Human-readable text | If present, include information from List: 196; Codes 95, 96, 98, and 99 (links for further information about accessibility) |
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