EPUB Accessibility Metadata

This metadata as outlined in the 1.0 Accessibility Specification Conformance and Discoverability can be found in the EPUB Package Document

Other techniques for implementing EPUB accessibility metadata are available: Display Techniques for Displaying Accessibility Metadata

This document provides techniques for meeting the guidelines of the User Experience Guide for Displaying Accessibility Metadata. It provides practical examples for extracting information from EPUB Package Document for showing it to the end users.

Some Schema.org accessibility metadata properties are descriptions of reading systems and not individual publications; this means they will not be appropriate for use inside the EPUB package. This includes the property "bookmarks," which indicates the ability of a reading system to allow users to set and navigate to bookmarks. In addition, some kinds of transformations described in Schema.org accessibility metadata are disallowed if a book is constructed to prevent transformations, but can only be provided if the reading system offers users control of that feature. Those features therefore cannot be declared present in the publication's metadata because not all reading systems that support the publication file will provide that feature.

Techniques

Screen Reader Friendly

Value: Yes / No / Unknown

This technique relates to Screen Reader Friendly principle.

This data is derived from the EPUB package metadata inside the Package Document:

If this metadata exists (ie. textual within accessModeSufficient by itself) then report Screen Reader Friendly: Yes

Important: This is not the same as visual, textual or textual, visual because the combination means that the book requires both visual and textual abilities to access the data, not textual alone. Only having accessModeSufficient be textual as a separate entry ensures the document is screen reader friendly.

As long as there is an entry that reads <meta property="schema:accessModeSufficient">textual</meta> the book can claim Screen Reader Friendly: Yes.

There may also be other accessModeSufficient entries with combinations of access modes such as textual, visual which indicate other ways to read the book.

When accessModeSufficient exists but does not have textual by itself, report Screen Reader Friendly: No.

When there is no accessModeSufficient metadata present, report Screen Reader Friendly: Unknown or not provided.

Example 1.1 (metadata present)

Metadata
UI

Screen Reader Friendly: Yes

(because textual was present by itself in accessModeSufficient)

Example 1.2 (multiple metadata accessModeSufficient fields present)

Metadata
UI

Screen Reader Friendly: Yes

(because textual was present by itself in accessModeSufficient)

Example 1.3 (metadata present but not Screen Reader Friendly)

Metadata
UI

Screen Reader Friendly: No

(because textual was not present by itself in accessModeSufficient)

Example 1.4 (metadata missing)

Metadata

{No Data}

UI

Screen Reader Friendly: Unknown

(because accessModeSufficient is not found at all in the metadata)

Full Audio

Values: Yes / (if No - Omit this section)

This technique relates to Full Audio principle.

This data is derived from the EPUB package metadata inside the Package Document:

If this metadata exists (ie. auditory within accessModeSufficient by itself) then report Full Audio: Yes.

Important: This is not the same as textual, auditory or auditory, textual as this indicates that the book requires both textual and auditory abilities to access the data, not auditory alone. Only having accessModeSufficient be auditory as a separate entry ensures the document contains full audio.

As long as you find <meta property="schema:accessModeSufficient">auditory</meta> the book can claim Full Audio: Yes.

There may also be other accessModeSufficient entries with combinations of access modes such as textual, visual which indicate other ways to read the book.

If you can not report that this is a book with full audio then do not present any information to the user for this category. Simply omit this section.

Example 2.1 (metadata present auditory)

Metadata
UI

Full Audio: Yes

(because auditory was found alone in accessModeSufficient)

Example 2.2 (metadata present but not a Full Audio ebook)

Metadata
UI

Omit this section

(Nothing presented to the user because auditory was not found alone in accessModeSufficient)

Example 2.3 (metadata not present)

Metadata

{No Data}

UI

Omit this section

(Nothing presented to the user because accessModeSufficient is not present at all in the metadata)

Accessibility Summary

Value: Textual Data from metadata

This technique relates to Accessibility Summary principle.

This data is pulled directly from the EPUB package metadata inside the Package Document:

We will be creating additional guidance for publishers on how to best write these summaries.

If the metadata does not exist this should say No Summary Available

This data could be in a language other than English but would be tagged as such.

Example 3.1 (metadata present)

Metadata
UI

Accessibility Summary:

This publication includes markup to enable accessibility and compatibility with assistive technology. Images, audio, and video in the publication are well-described in conformance with WCAG 2.0 A.

Example 3.2 (metadata missing)

Metadata

{No Data}

UI

Accessibility Summary: None provided

Accessibility Conformance (Strings)

These techniques are for public draft of EPUB Accessibility 1.1, and the pre defined strings may change

Predefined Token Values:

This technique relates to Accessibility Conformance principle.

If the string is one of our predefined token values defined in EPUB Accessibility 1.1:

  • EPUB-A11Y-11_WCAG-20-A report it as EPUB Accessibility, WCAG2.0-A
  • EPUB-A11Y-11_WCAG-20-AA report it as EPUB Accessibility, WCAG2.0-AA
  • EPUB-A11Y-11_WCAG-20-AAA report it as EPUB Accessibility, WCAG2.0-AAA
  • EPUB-A11Y-11_WCAG-21-A report it as EPUB Accessibility, WCAG2.1-A
  • EPUB-A11Y-11_WCAG-21-AA report it as EPUB Accessibility, WCAG2.1-AA
  • EPUB-A11Y-11_WCAG-21-AAA report it as EPUB Accessibility, WCAG2.1-AAA

If the value is anything other than the six tokens listed above, then providing the raw string value as is.

Example Conformance (metadata present token)

Metadata
UI

Accessibility Conformance: EPUB Accessibility, WCAG 2.1 AA

Example 4.1 (metadata present non-token string)

Metadata
UI

Accessibility Conformance: WCAG AA

Certified By

Value: Textual Data from metadata

This technique relates to Certified By principle.

This data is pulled directly from the EPUB package metadata inside the Package Document:

If the metadata does not exist this should say None provided

Example 5.1 (metadata present 3rd party)

Metadata
UI

Certified By: 3rd Party Company Name

Example 5.2 (metadata present self Certified)

Metadata
UI

Self Certified By: Publisher Name

Example 5.3 (metadata missing)

Metadata

UI

Certified By: None provided

Certifier Credential

Value: Potentially linked textual data from metadata

This technique relates to Certifier Credential principle.

This data is pulled directly from the EPUB package metadata inside the Package Document:

This metadata could be a simple text string in which case you would just display it, or it could be a URI to the certifier’s credential web page.

If the metadata value is a URI, you could have some standard certification logo which would be clickable and link to the certifier’s credential webpage.

If you do not wish to have clickable links here, you may omit them as long as you make the links available in the section All Accessibility Metadata, described below.

If you are aware of a list of organizations who offer third-party certification, a short list of certifier’s logos could be cached and displayed when appropriate. For example:

Example 6.1 (Text)

Metadata
UI

Certifier Credential: XYZ Certified Accessible

Example 6.2 (Generic 3rd party URL)

Metadata
Metadata

Certifier Credential

There may be an image that is associated with specific Certifier Credential image (ie. Mark/Stamp/Seal) which could be used here. If you would like to display this image, or any other, you would need to be coordinate this out of band with the certifier agency as it is not part of the metadata delivered with the book.

Or

Example 6.3 (metadata missing)

Metadata

{No Data}

UI

Certifier Credential: None provided

Certifier Report

Value: Potentially linked textual data from metadata

This technique relates to Certifier Report principle.

This data is pulled directly from the EPUB package metadata inside the Package Document:

Ideally you would have a clickable link to the certification accessibility report.

If you do not wish to have clickable links here, you may omit them as long as you make the links available in the section All Accessibility Metadata, described below.

Example 7.1 (URL)

Metadata
UI

Certifier Report

ACME Inc. Report webpage

Or

Example 7.2 (metadata missing)

Metadata

{No Data}

UI

Omit this section

(Omit this section if the metadata is missing, as most of the time there will be no report available.)

Hazards

Values: flashing, motion simulation, sound, no flashing, no motion simulation, no sound, none, or unknown.

This technique relates to Hazards principle.

This data is found in the EPUB package metadata inside the Package Document:

Hazards are the only metadata which can be expressed as either positive or negative statements, so metadata authors can confirm either the presence of the hazard, such as flashing, or the absence of the hazard, noFlashingHazard and similarly for sound / noSoundHazard and motion / noMotionSimulationHazard. There is also the metadata value none, which covers all three categories and corresponds to noFlashingHazard, noSoundHazard and noMotionSimulationHazard.

In the section All Accessibility Metadata Hazards will be displayed exactly how the publisher provided them so simplifying here with using none can be an option instead of saying explicitly no Sound, no Flashing, no Motion Simulation

Example 8.1 (metadata present flashing)

Metadata
UI

Hazard: Flashing

(because flashing was found in accessibilityHazard)

Example 8.2 (metadata present motionSimulation)

Metadata
UI

Hazard: Motion Simulation

(because motionSimulation was found in accessibilityHazard)

Example 8.3 (metadata present sound)

Metadata
UI

Hazard: Sound

(because sound was found in accessibilityHazard)

Example 8.4 (multiple hazards present)

Metadata
UI

Hazard: Sound, Motion Simulation, and Flashing

(because sound, motionSimulation, and flashing were all found in accessibilityHazard)

Example 8.5 (metadata present none)

Metadata
UI

Hazards: none

(because none was found in accessibilityHazard)

Example 8.6 (metadata present: noFlashingHazard, noSoundHazard, and noMotionSimulationHazard)

Metadata
UI

Hazards: No Flashing, No Sound, No Motion Simulation

Or

Hazards: none

(because none is equivalent to all three noSoundHazard, noMotionSimulationHazard, and noFlashingHazard combined.)

Example 8.7 (metadata not present) or (metadata present unknown)

Metadata

{No Data}

or

UI

Hazards: unknown

We want to make the distinction here between No Hazards and missing or unknown hazard metadata therefore for the missing metadata case we need to inform the user we don’t know about any hazards which may or maynot be present.

All Accessibility Metadata

Value: Link to complete list of all metadata fields

This technique relates to All Accessibility Metadata principle.

Here are all the possible accessibility metadata properties.

This section can either be a separate page that is linked to or better yet an HTML Summary/Details element that users can expand to get all the accessibility metadata field elements. Here you would expose: accessibilityFeature, accessibilityHazard, accessMode, accessModeSufficient, as well as all the accessibility metadata and conformance metadata listed above.

Example 9.1 (all metadata fields present)

Metadata
UI

Accessibility Features:

  • Alternative Text

  • Long Descriptions

  • Print Page Numbers

Accessibility Hazards:

  • No Sound Hazard

  • No Motion Simulation Hazard

  • No Flashing Hazard

AccessMode:

  • Visual

  • Textual

Access Mode Sufficient:

  • Visual

  • Textual

  • Both Visual and Textual

Certified By:

ACME Certification

Certifier’s Credential:

https://ACME-Certification.org/

Conforms To:

http://www.idpf.org/epub/a11y/accessibility-20170105.html#wcag-a

Accessibility Summary:

This publication includes markup to enable accessibility and compatibility with assistive technology. Images, audio, and video in the publication are well-described in conformance with WCAG 2.0 A.

Example 9.2 (all metadata fields missing)

Metadata

{No Data}

UI

Accessibility Features:

None provided

Accessibility Hazards:

None provided

AccessMode:

None provided

Access Mode Sufficient:

None provided

Certified By:

None provided

Certifier’s Credential:

None provided

Conforms To:

None provided

Accessibility Summary:

None provided

Acknowledgements

Contributors

Reviewers