User Experience Guide for Displaying Accessibility Metadata 1.0

Final Community Group Report

Latest published version:
Latest editor's draft:
Charles LaPierre (Benetech)
Gregorio Pellegrino (Fondazione LIA)
GitHub w3c/publ-a11y
File an issue
Commit history
Pull requests


Finding, buying, and finally reading a publication is a very personal experience. For most of us this is routine. We go to a bookstore, search for the title we are interested in or perhaps browse the best sellers list, then purchase and start reading the publication.

Now consider you are blind and rely on an assistive technology to read the publication. You wonder: will my screen reader work with this title; are there image descriptions that will be spoken to describe these images; are there page numbers which are accessible; is the reading order correct so I don't hear a caution after reading a paragraph which could be dangerous? These are just a few of the accessibility concerns consumers have when trying to purchase and ultimately read a digital publication.

The good news is more and more publishers are creating publications that are Born Accessible (i.e., accessible from the outset, not fixed later) and getting the accessibility validation or audit done by independent organizations.

This document proposes a shared framework for presenting publication accessibility metadata in a user-friendly manner.

Status of This Document

This specification was published by the Publishing Community Group. It is not a W3C Standard nor is it on the W3C Standards Track. Please note that under the W3C Community Final Specification Agreement (FSA) other conditions apply. Learn more about W3C Community and Business Groups.

GitHub Issues are preferred for discussion of this specification.

1. General Overview

This document helps those who wish to render accessibility metadata directly to users understand how to represent machine-readable accessibility metadata in a user-friendly User Interface / User Experience (UI/UX).


This document presents high-level principles without going into technical issues related to the different metadata standards in the publishing industry.

Therefore, techniques are available that illustrate to developers how to retrieve data to show the information outlined in this document.

Metadata found either inside a digital publication or in a corresponding external record may have important accessibility information that helps end users find and determine if the publication can meet their specific accessibility needs.

Most metadata is meant to be machine-readable so that it aids in user search queries such as Find all digital publications that contain large print, or braille, or that meet a certain level of accessibility conformance.

The exception to this rule is the accessibility summary which, if present, describes in human-readable prose the accessibility features present in the publication as well as any shortcomings, when applicable. This summary is intended for direct presentation to end users.

Here is an example of what a user-friendly accessibility metadata web page could look like:

2. Discovering Accessible Content

The guidelines for presenting accessibility metadata detailed in this document are intended to improve the user experience when readers browse the catalog entry for a publication. However, accessibility metadata also has a vital role to play in helping readers discover publications that are accessible for them. Publication providers, such as vendors and libraries, are encouraged to create searching and filtering tools that interpret accessibility metadata to aid in discovery. (A full discussion of search and filtering issues is out of scope for this document, but this section provides some guidance until further research can be carried out.)

While every user has different accessibility needs, meeting the Web Content Accessibility Guidelines (WCAG) 2.0 requirements, even at level A, is a baseline that ensures a publication will be widely accessible. Publication providers may therefore wish to create specific search capabilities to permit users to find publications that have declared conformance to WCAG at any level. We suggest the creation of an "Accessible" search filter that only returns publications with metadata that indicates conformance to the user-selected WCAG Level — A, AA, or AAA.

Publications with full audio created for mainstream use provide important access for many users with disabilities even though they are not accessible to all. (Note that these publications differ from traditional audiobooks in that the audio accompanies the full or partial text of the publication.) Publication providers may already have search tools aimed at finding traditional audiobooks, since they are popular and common, but even if not, this would be a good addition to the suite of tools for finding accessible publications. Publications with full audio may not pass WCAG requirements, however, because they are targeted at a specific audience rather than broadly accessible. As a result, they would not be found using the Accessible search suggested above.

Any of the metadata fields discussed in detail below could also be used as a filter — a Screen-reader accessible search would be valued by screen reader users, and a way to ensure no publications with hazards are downloaded would be valued by those with light-sensitive epilepsy or other hazard-related conditions. But if only a single additional search filter fits best in a site's UI, a tool for finding accessible materials that declare conformance to WCAG 2.0 is the best choice to provide.

3. UI Technical Details

When you have accessibility metadata about a digital publication, it is important to share this information in as user-friendly a way as possible. At a very high level, when displaying information about a digital publication, you may only want to acknowledge that Accessibility Features or Accessibility Information is available. If the user would like to get at this information, they can click a text or image link which will then provide the information that is discussed below.


When a publisher does not provide any accessibility metadata for a publication, a statement should be displayed to the user informing them that no information was supplied.

In this example, a link to the accessibility information is provided with a traditional textual link.

Alternatively, this link to the accessibility information could be provided with a clickable image.

3.1 Techniques

To assist developers in implementing these guidelines, in-depth notes are available to explain how to extract information from publishing industry metadata standards.

At the time of publishing this document the available techniques for metadata standards are:

4. Order of Key Information

Ordering the supplied metadata in a meaningful and consistent way for users helps them easily understand the strengths and weaknesses of each publication. Consequently, the most important information appears first to help the user quickly determine if the publication will meet their specific needs.

The recommended ordering of information is as follows:

  1. Screen Reader Friendly

  2. Full Audio (if present)

  3. Accessibility Summary

  4. Accessibility Conformance

  5. Certified By

  6. Certifier’s Credential

  7. Certifier’s Report (if present)

  8. Hazards

  9. All Accessibility Metadata

The two most important accessibility accommodations to list are if the publication is Screen Reader Friendly and has Full Audio. A screen reader friendly publication implies all text is accessible and any images are described, if necessary. A publication that indicates it includes full audio lets the user will know the entire publication can be read through audio playback.

The next important piece is the Accessibility Summary which is metadata describing all the accessibility accommodations provided by this publication. Following this are the accessibility conformance information (what level of conformance was reached, who certified it, and any certification credentials).

Finally displaying any hazards if present and linking to all the accessibility metadata including all the specific accessibility features such as: image descriptions, MathML, a table of contents, etc.

More detailed information about these fields is provided in the following sections.

4.1 Screen Reader Friendly

Value: Yes / No / Unknown


A Yes/No/Unknown answer to the question "Can a screen-reader user read this publication?". This can be based on a combination of metadata fields, if needed, that establish that the primary content of the publication is available in true text and is not an image of text.


Most available digital publications include their content in true text and can report that they are screen reader friendly. Exceptions would include publications where critical content is included only in images, such as graphs, charts, or equations presented as images, and publications with a fixed appearance created by having an image of each page instead of true text.


4.2 Full Audio

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


An indication that this publication can be read in full auditorily. This designation applies even if the text is also available with the audio.


Some users, including users with dyslexia or visual impairments, seek publications they can use entirely by listening. Full Audio metadata is important to the discovery process for these users. Publication providers may already be designating "audiobooks" as a separately searchable set based on the popular definition of an audiobook as an audio-only experience. Publications that include full text and full audio may not currently be grouped with audiobooks, so exposing this metadata adds additional publications to the list of titles audio users might be interested in.

Audiobooks presented without text are considered optimized publications. They do not meet all accessibility requirements, and therefore will not be discovered when filtering for "accessible" publications, but they provide access to the publication for specific users who require audio. Providing a way for users to search a collection for all publications with full audio will support these users and including this information in the metadata displayed will also alert users for whom audio is inaccessible. This piece of metadata should be included only if the value is "Yes". Since most digital publications available do not include audio, it is only important to include this metadata in the user interface for those that do.


4.3 Accessibility Summary

Value: Textual Data from metadata


A plain language explanation of the overall accessibility of the publication. The accessibility summary should contain information that would make it easy for an end user to determine if the publication is accessible to them. Educators would also be able to determine if the publication was accessible for use in a classroom or an online course.


A human readable description is needed to be available for an end user or an educational professional to determine if the title will be accessible to them personally, or to the students. It should be easy to read and understand if it will be suitable for use by persons with disabilities. This determination must be made before the end user purchases or selects the title, and must be determined before a title is selected for a course.


4.4 Accessibility Conformance

Value: Textual Link based on Metadata


To report the accessibility conformance of a publication, metadata for accessibility conformance should be provided. It declares the accessibility standard or accessibility specifications to which the publication conforms. The value can be a URL or a code which identifies the accessibility standard or accessibility specifications.


In case of EPUB publications, it will usually point to the EPUB Accessibility specifications or WCAG.


If a publication is optimized for a particular user group (e.g., an audiobook), it would not conform to WCAG guidelines, but it may be perfectly useable by a particular group (e.g., persons who are blind). In this case, the accessibility conformance metadata should identify the specification used to create the optimized publication.


Discovery metadata enables publications to have their accessibility exposed regardless of the overall accessibility of the publication. A publication optimized for a particular group, such as an audiobook, would not meet WCAG 2.0, but it would be fully accessible to many people. The conformance metadata details the accessibility of the publication, which allows end users and educators to evaluate the suitability of the publication for individuals.


At the time of publication of this document there is an open issue #1767 (Is zero tolerance for accessibility conformance practical?) in the working draft of EPUB Accessibility 1.1. It may change the values for the Accessibility Conformance metadata in the future revision of these guidelines.


4.5 Certified By

Value: Textual Data from metadata


The Certified By property specifies the name of the party that certified the content. The certifier of the content could be the same party that created or published the publication, or a third-party accessibility certifier.


When the metadata about a publication declares that it conforms to an accessibility specification reaching a certain level of WCAG conformance, the party making this assertion must be identified.


4.6 Certifier Credential

Value: Potentially linked textual data from metadata


The Certifier Credential indicates the name of the credential or badge that establishes the authority of the certifying party.


Stating that the organization certifying this content has a credential recognized by the community gives a higher level of trust as to the accuracy of the conformance level reached.


4.7 Certifier Report

Value: Potentially linked textual data from metadata


The Certifier Report is an URL pointing to a web page where the certifier publishes a report detailing the accessibility of the publication.


Providing a link to the complete report allows end users and organizations to review the specifics of its conformance or failure to standards. The user interface should display a link to the report.


4.8 Hazards

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


Hazards are a list of possible ways in which this publication could be physiologically dangerous for some users (e.g., flashing elements, background sounds, and motion simulation).


Unlike other accessibility properties, the presence of hazards can be expressed either positively or negatively. This is because users are more often looking for content that is safe for them. This section should always be displayed; indicate that no metadata was provided if that is the case.


4.9 All Accessibility Metadata

Value: Link to complete list of all metadata fields


This field provides the listing of all accessibility metadata for the publication. It can be a hyperlink to another page or can be listed in HTML summary/details element. It should include metadata for accessibilityFeature, accessibilityHazard, accessMode, accessModeSufficient and all the accessibility metadata and conformance metadata listed above.


A complete list of accessibility metadata is important for advanced users who would like to know about the presence of specific accessibility features in the publication. This listing is also important for verification of the interpretation of the accessibility metadata provided according to this user experience guide.


A. Acknowledgements

This section is non-normative.

A.1 Contributors

A.2 Reviewers

A.3 Intellectual Property Rights