Summary

Include accessibility evaluation metadata to enable conformance discovery and provide identification of the evaluator and their credentials.

Examples

<metadata>
  <meta property="dcterms:conformsTo">
     EPUB Accessibility 1.1 - WCAG 2.0 Level AA
  </meta>
  <meta property="a11y:certifiedBy">Dewey, Checkett and Howe</meta>
  <meta property="a11y:certifierCredential">Certifiably Accessible</meta>
  <link rel="a11y:certifierReport"
        href="https://example.com/reports/a11y/pub.html"/>
  …
</metadata>

<metadata>
  <meta name="dcterms:conformsTo"
        content="EPUB Accessibility 1.1 - WCAG 2.0 Level AA"/>
  <meta name="a11y:certifiedBy" content="Dewey, Checkett and Howe"/>
  <meta name="a11y:certifierCredential" content="Certifiably Accessible"/>
  <meta name="a11y:certifierReport"
        content="https://example.com/reports/a11y/pub.html"/>
  …
</metadata>

Frequently Asked Questions

Does the a11y: prefix have to be declared in the EPUB package document?

Technically, no, but best practice is to always declare the prefix. EPUB has a concept of "predefined prefixes", which are prefixes that can be used without being declared. In practice, however, older versions of the epubcheck validation tool will flag newer predefined prefixes as errors, as they are unaware of newer additions. Declaring the prefix ensures there will not be validation issues.

The a11y: prefix is declared as follows:

<package … prefix="a11y: http://www.idpf.org/epub/vocab/package/a11y/#">

Explanation

Evaluation metadata provides additional information about the individual or organization that has assessed a publication against accessibility standards. It also allows identification of the standard(s) the publication conforms.

All evaluation metadata described in this section with an a11y: prefix are defined in the EPUB Accessibility Vocabulary.

dcterms:conformsTo

An established standard to which the described resource conforms.

The dcterms:conformsTo property in included in a publication when that publication has been checked and confirmed to conform to an accessibility standard. The value is a string or URL that identifies the standard.

Note

The property is only included when a publication meets the requirements of a standard. It is not used to indicate failure. Use the schema.org accessibilitySummary property to record information about failures.

For EPUB, this property identifies both the version of the EPUB Accessibility standard the publication conforms to as well as the version and level of WCAG conformance. The value of the string must conform to the following pattern:

EPUB Accessibility 1.1 - WCAG 2.X Level (A|AA|AAA)

The value "2.X" is replaced by the version of WCAG (e.g., 2.0 or 2.1) and "(A|AA|AAA)" is replaced by which of those levels was achieved.

For example, the following values are currently valid to use with this property:

• EPUB Accessibility 1.1 - WCAG 2.0 Level A
• EPUB Accessibility 1.1 - WCAG 2.0 Level AA
• EPUB Accessibility 1.1 - WCAG 2.0 Level AAA
• EPUB Accessibility 1.1 - WCAG 2.1 Level A
• EPUB Accessibility 1.1 - WCAG 2.1 Level AA
• EPUB Accessibility 1.1 - WCAG 2.1 Level AAA

For more information about these conformance values, please refer to the Publication conformance section of the EPUB Accessibility specification.

EPUB 3 usage:

<meta property="dcterms:conformsTo">
      EPUB Accessibility 1.1 - WCAG 2.0 Level AA
</meta>

EPUB 2 usage:

<meta
      name="dcterms:conformsTo"
      content="EPUB Accessibility 1.1 - WCAG 2.0 Level AA"/>

Note

The EPUB Accessibility 1.0 specification was developed by the IDPF and used conformance URLs that contained that organization's domain (idpf.org).

As IDPF no longer exists — it was merged into W3C — the EPUB Working Group decided to drop the use of IDPF URLs and move to the string-based system described earlier in this section. While the IDPF URLs remain valid for existing content, publishers conforming to the Accessibility 1.0 requirements are encouraged to move to declaring conformance to the new 1.1 specification.

Publications that conform to the EPUB Accessibility 1.0 standard also conform to the 1.1 standard.

The following list maps the old identifiers to their replacements:

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

New: EPUB Accessibility 1.1 - WCAG 2.0 Level A

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

New: EPUB Accessibility 1.1 - WCAG 2.0 Level AA

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

New: EPUB Accessibility 1.1 - WCAG 2.0 Level AAA

a11y:certifiedBy

Identifies a party responsible for the testing and certification of the accessibility of an EPUB Publication.

The a11y:certifiedBy property is included in a publication when it has been reviewed for accessibility conformance. The EPUB Accessibility specification requires that this property be set even when the publication does not meet accessibility requirements.

EPUB 3 usage:

<meta property="a11y:certifiedBy">Dewey, Checkett and Howe</meta>

EPUB 2 usage:

<meta name="a11y:certifiedBy" content="Dewey, Checkett and Howe"/>

a11y:certifierCredential

Identifies a credential or badge that establishes the authority of the party identified in the certifiedBy property to certify content accessible.

The a11y:certifierCredential property is used to provide more information about the credentials of the certifier to carry out accessibility evaluations.

The property can either be a text field with the name of the credential held, or it can be a link to a description of the credential.

EPUB 3 usage:

<meta property="a11y:certifierCredential">Certifiably Accessible</meta>
<link rel="a11y:certifierCredential"
      href="https://example.com/a11y/credential"/>

EPUB 2 usage:

<meta name="a11y:certifierCredential" content="Certifiably Accessible"/>
<meta name="a11y:certifierCredential"
      content="https://example.com/a11y/credential"/>

a11y:certifierReport

Provides a link to an accessibility report created by the party identified in the certifiedBy property.

When an accessibility conformance report for the publication is publicly available, the a11y:certifierReport property can be used to provide a link to it. The user agent can then offer the user the option to access this report to discover more information about the title.

EPUB 3 usage:

<link rel="a11y:certifierReport"
      href="https://example.com/reports/a11y/pub.html"/>

EPUB 2 usage:

<meta name="a11y:certifierReport"
      content="https://example.com/reports/a11y/pub.html"/>

Related Links

• EPUB Accessibility — Conformance Reporting
• EPUB Accessibility Vocabulary