Evaluation Metadata

Category:

Summary

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

Examples

Example 1 — Package Document metadata (EPUB 3)

The following example shows a complete set of evaluation metadata for a publication that conforms to the EPUB Accessibility 1.1 specification at WCAG Level AA.

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

Example 2 — Package Document metadata (EPUB 2)

The following example shows how to express evaluation metadata in an EPUB 2 publication using the meta tag's name and content attributes.

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

Frequently Asked Questions

Does it matter who evaluates an EPUB publication?

Not so long as the evaluator knows the requirements of the EPUB Accessibility standard and is practiced in their application. A publisher — whether a large organization or a self-publisher — can evaluate their own content or they can contract with an accessibility professional to review the content.

A publisher can identify themself as the evaluator of their work even if they have another individual or organization review the work, but they should be confident in the evaluation when doing so.

In some regions, a central authority may be responsible for evaluating all publications. In this case, that authority will typically add their information as the evaluator.

Is automatic validation enough to certify a publication?

No. Running a machine validator like Ace by DAISY is very useful but never sufficient to make an accessibility claim. Automated tools have limitations on what they can check for and cannot evaluate the quality of various affordances (like alternative text and descriptions).

Manual evaluation is always required. The Ace SMART tool helps evaluators go through all of the requirements for validation and is able to build on the reports generated by the Ace tool.

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 "reserved 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/#">

Properties

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.

When the dcterms:conformsTo property is included in a publication, it indicates that someone has checked and confirmed the publication conforms to a standard. The value of the element is a string or URL that identifies the standard.

In particular, the EPUB Accessibility standard from version 1.1 onward uses this property to identify publications that conform to its requirements. The value of the property identifies both the version of the standard the publication conforms to as well as the version and level of WCAG conformance, and must match the following pattern:

EPUB Accessibility X - WCAG Y Level Z

where:

X is replaced by the version of the W3C EPUB Accessibility standard. (1.1 or higher).
Y is replaced by the version of WCAG 2 (2.0, 2.1, or 2.2).
Z is replaced by the WCAG conformance level that was achieved (A, AA, or AAA).

For example, the following values are currently valid to use with this property to indicate conformance to the EPUB Accessibility 1.2 standard at WCAG 2 Level A or AA:

EPUB Accessibility 1.2 - WCAG 2.2 Level AA
EPUB Accessibility 1.2 - WCAG 2.2 Level A
EPUB Accessibility 1.2 - WCAG 2.1 Level AA
EPUB Accessibility 1.2 - WCAG 2.1 Level A
EPUB Accessibility 1.2 - WCAG 2.0 Level AA
EPUB Accessibility 1.2 - WCAG 2.0 Level A

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 1.2 - WCAG 2.2 Level AA
</meta>

EPUB 2 usage:

<meta
  name="dcterms:conformsTo"
  content="EPUB Accessibility 1.2 - WCAG 2.2 Level AA"/>

Transitioning from EPUB Accessibility 1.0

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

Conformance to this version used the package document metadata's link element with idpf.org URLs, like in the following example:

<link
     rel="dcterms:conformsTo"
     href="http://www.idpf.org/epub/a11y/accessibility-20170105.html#wcag-aa"/>

As IDPF no longer exists, the W3C Publishing Working Group decided to drop the use of IDPF URLs for the conformance identifier and move to the string-based identifier system described earlier. While the IDPF URLs remain valid for existing 1.0 content, publishers conforming to the Accessibility 1.0 requirements are encouraged to move to declaring conformance to the new W3C standard.

Publications that conformed to the IDPF 1.0 standard also conform to the 1.1 of the W3C standard. The following list maps the old identifiers to their latest replacements:

Note

Due to changes in metadata requirements in the EPUB Accessibility 1.2 standard, EPUB publications that conformed to the 1.0 standard cannot automatically declare declare conformance to 1.2 to above. Conformance to the latest discoverability metadata and EPUB requirements will first have to be confirmed.

WCAG 2.0 Level A

1.0 markup:

<link rel="dcterms:conformsTo"
       href="http://www.idpf.org/epub/a11y/accessibility-20170105.html#wcag-a"/>

1.1 markup:

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

WCAG 2.0 Level AA

1.0 markup:

<link rel="dcterms:conformsTo"
       href="http://www.idpf.org/epub/a11y/accessibility-20170105.html#wcag-aa"/>

1.1 markup:

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

WCAG 2.0 Level AAA

1.0 markup:

<link rel="dcterms:conformsTo"
       href="http://www.idpf.org/epub/a11y/accessibility-20170105.html#wcag-aaa"/>

1.1 markup:

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

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 to indicate who reviewed it for accessibility conformance. The EPUB Accessibility specification requires that publishers set this property 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 identifies a credential the certifier possesses — specifically, one 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, publishers can use the a11y:certifierReport property to provide a link to it. Vendors and reading systems can then offer users 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"/>

a11y:contactEmail

Provides an email address for requesting more information about the accessibility of the EPUB publication or to report issues with the work.

Publishers often rely on spot checking and automation to verify that their content meets accessibility requirements. The accessibility contact email is intended to provide a way for users to contact the individual or department responsible for accessibility if they discover an issue with their publication. It is also meant as a way for users to contact the publisher if they require more information about the accessible qualities of a publication before purchasing it.

Note

The a11y:contactEmail property is not meant to capture a general feedback address for all publisher inquiries.

EPUB 3 usage:

<meta property="a11y:contactEmail">
   accessibility-info@example.com
</meta>

EPUB 2 usage:

<meta name="a11y:contactEmail"
  content="accessibility-info@example.com"/>

Applies To

EPUB 3	EPUB 2	Audiobooks
Yes	Yes	No