The accessibility of a publication is useful to know regardless of a person's abilities, as features such as the ability to make visual adjustments make for a better reading experience for everybody. This document proposes a shared framework for presenting publication accessibility metadata declarations in a user-friendly manner — to offer the information to end users in a way that is easy to understand regardless of their technical knowledge and is consistent across different publications and different digital catalogs.



Reading a publication is a very personal experience. For most people this is routine, and little consideration is given to how the title was obtained before it is read. Users may go to a bookstore, search for the title to purchase online, or have the title selected for them by an instructor for a class.

Now consider that the person is blind and relies on assistive technology. The user needs that technology to assist them in the purchase process as well as to read the publication. The person may wonder: will the 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 a caution after reading a paragraph which could be dangerous will be announced? All of these, and more accessibility concerns are potential issues 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.

General overview

This document helps those who wish to render accessibility metadata directly to users understand how to represent the accessibility claims inherent in machine-readable accessibility metadata in a user-friendly User Interface / User Experience (UI/UX). This document targets implementers such as bookstores, retailers, distributors etc. Content creators will benefit from reading these Principles and are encouraged to follow EPUB Accessibility 1.1 Conformance and Discoverability Requirements section and its techniques.

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 claims that helps end users find and determine if the publication can meet their specific accessibility needs.

All accessibility metadata is meant to be machine-readable – apart from the accessibility summary - in this way accessibility metadata can be extracted and displayed uniformly across different publications and localized to different user interface languages.

One important aspect is that the role of the Accessibility Summary metadata has changed in the latest version of the EPUB Accessibility specification, so a more in-depth analysis in the Accessibility summary section is recommended.

This document offers guidance on how to aggregate and display claims inherent in metadata to end users; these are not strict guidelines, but suggestions for providing a consistent experience for users through different portals. Different implementers may choose to implement these guidelines in a slightly different way, some examples can be seen in the Implementations section of the document.

Accessibility claims and declarations

When presenting accessibility metadata provided by the publisher, it is suggested that the section is introduced using terms such as "claims" or "declarations." This heading should clearly convey to the end user that the information comes directly from the publisher and represents the accessibility information that the publisher intends to communicate.

Publisher metadata ecosystem

It is helpful to visualize the metadata workflow. The image below shows the path publisher's metadata takes to get to the end user through a distributor or library. The two paths visualized for EPUB accessibility metadata and ONIX correspond to the techniques referenced in the linked techniques documents.

Flowchart: Metadata Ecosystem
Digital Publication Ecosystem flows into four areas: Metadata Delivery, Accessibility Metadata spec, Metadata Processing, and Resulting Statements
Flowchart's Detailed Description

The digital publication ecosystem has two main channels of "Metadata Delivery": "Embedded inside the EPUB", and "Thru the supply chain."

From the "Metadata Delivery" this flows into the "Accessibility Metadata spec" where from "Embedded inside the EPUB" flows into the "EPUB Accessibility Metadata 1.1 specification", and from "the supply chain" flows into the "ONIX Accessibility metadata." At this same level the "Crosswalk" links between the EPUB and ONIX metadata.

From here both flow down into the "Metadata Processing" layer where the EPUB metadata gets processed through the "Display Techniques for EPUB Accessibility Metadata", and the "ONIX accessibility metadata" is processed through the "Display Techniques for ONIX Accessibility Metadata."

Finally from the "Metadata Processing" layer both the Display Techniques for EPUB and ONIX flow into the "Resulting Statements" layer "User Experience Guide for Displaying Accessibility Metadata"

Metadata 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:

Publishers update their ONIX records as needed. We expect "unknown" accessibility metadata may be initially provided but may change as more information becomes available. For this reason, implementors should be prepared to update the accessibility metadata as new ONIX feeds are made available.

General information (supplement the bibliographic information)

To solve the problem of displaying the accessibility metadata in a human readable form, vendors will determine their correct statement to display (from the User Experience Guide) by parsing the metadata and using the appropriate Display Techniques document.

The product details provide precious information about the usability of the book in relation to specific user needs. The following information should always be displayed:

Why this information is important for accessibility

Key accessibility information

When the content creator does not provide any accessibility metadata for a publication, the three pieces of key information that should always be present can still be shown (with an indication that the information is missing): Visual adjustments, Supports nonvisual reading, and Conformance.

This document does not define the order in which to show the key accessibility information; each implementer can decide the preferred order for showing the accessibility information that follows.

Visual adjustments

This key information should always be displayed, even if there is no metadata (See the examples where the metadata is not known).

Indicates if users can modify the appearance of the text and the page layout according to the possibilities offered by the reading system.

This field answers whether visual adjustments are possible, not possible, or unknown.

Readers with visual impairments or cognitive disabilities need the ability to change the color of text and its background (contrast), the font family and font size used, as well as spacing between letters, words, sentences, or paragraphs.

Knowing that a publication can reflow to fit the reading system's display area is not sufficient to know that modifications to the font, spacing, and colors are possible or that the changes will not cause other readability issues (e.g., text being clipped by its container).


The examples are provided as lists of possible descriptive and compact explanations for flexibility of adoption.

Metadata techniques

Supports nonvisual reading

This key information should always be displayed, even if there is no metadata (See the examples where the metadata is not known).

Indicates whether all content required for comprehension can be consumed in text and therefore is fully available to assistive technologies and reading systems using text-to-speech or electronic braille functionality.

The terms "electronic braille" and "refreshable braille" are used interchangeably, which denotes a device with pop-up pins to present the braille on a tactile screen.

This field answers whether nonvisual reading is possible, not possible, or unknown.

Digital publications with essential content included in non-textual form (such as graphs, tables or equations presented as images, videos, etc.) must include textual alternatives to ensure that users reading with other senses than sight (mainly auditory and tactile) have access to the same information as visual readers. These textual alternatives can include extended descriptions, transcripts, captions, etc. depending on the nature of the nonvisual content.


The examples are provided as lists of possible descriptive and compact explanations for flexibility of adoption.

Metadata techniques


This key information should always be displayed, even if there is no metadata (See the examples where the metadata is not known).

Identifies whether the digital publication claims to meet internationally recognized conformance standards for accessibility.

Conformance metadata often uses terminology that most people will not understand, and therefore simple statements should be provided when EPUB accessibility and WCAG levels are identified.

If the publication does not include a conformance claim, the statement should indicate that conformance could not be determined.

In most cases, people will want to know more about the conformance and certification of the publication. The certifying organization should be identified along with their credentials and placed immediately after the conformance statement.

Conformance statements

The following list explains the meaning of each recommended conformance statement.

This publication meets accepted accessibility standards.

The publication contains a conformance statement that it meets the EPUB Accessibility and WCAG 2 Level AA standard.

This publication meets minimum accessibility standards.

The publication contains a conformance statement that it meets the EPUB Accessibility and WCAG 2 Level A standard.

This publication exceeds accepted accessibility standards.

The publication contains a conformance statement that it meets the EPUB Accessibility and WCAG 2 Level AAA standard.

Certifier's name
Identifies the organization providing the certification review or process for certification.
Certifier's Credentials
If the certifier has a badge or a credential, then the text is provided. If there is a link to their credential, then this can be provided as a link. If the certifier has a logo or badge, this can be displayed. The display of the logo or badge can be arranged between the certifier and the distributor showing the accessibility metadata.
This publication's accessibility conformance has not been associated with accepted standards.

The publication contains a conformance statement that is not to the EPUB Accessibility standard.

The publication does not include a conformance statement.

The conformity to a standard of this publication is unknown.

Detailed conformance information

The following information can be placed in a section that shows the details of the conformance information.

Conformance Statement
Identifies the accessibility specification and the conformance level to which the publication assertions are made. When the publication claims to conform to more than one specification, additional conformance statements may be provided.
Certification date
If the date of the certifier's evaluation is provided, then this would be of interest. This is normally associated with the certifier.
Certifier's Report
If a link to a report is provided, this may be of interest.


Three examples are provided for the conformance statement, one shows a statement that claims to meet recommended accessibility standards and a second that claims to meet the minimum level. The third shows a publication with unknown accessibility.

The examples present the conformance statement, the certifier, the certifiers credentials and is followed by the detailed conformance information section

Metadata techniques

Pre-recorded audio

This key information can be hidden if metadata is missing.

Indicates the presence of pre-recorded audio and specifies if this audio is standalone (an audiobook), accompanies text (embedded audio and video clips), or represents an alternative to the text (synchronized text-audio playback).

Audiobooks created for mainstream use provide important access for many users with disabilities even though they are not accessible to all. As they grow in popularity, audiobooks may provide more accessibility options in the future.

Some publications provide audio (including audio in video) in addition to text. In this case, it is important that the user is informed that they may not be able to access all content in the book.

Some publications provide pre-recorded audio with text synchronization. Users with hearing impairments still can access the full content of these books.


The examples are provided as lists of possible descriptive and compact explanations for flexibility of adoption.

Metadata techniques

Charts, diagrams, and formulas

This key information can be hidden if metadata is missing.

Indicates the presence of formulas (including math, chemistry, etc.), graphs, charts, and diagrams within the title and whether these are in an accessible format or available in an alternative form (e.g., whether formulas are navigable with assistive technologies, or whether extended descriptions are available for complex images).

This group should be displayed only if the metadata indicates the presence of formulas or charts and graphs within the title, otherwise it can be hidden.


The examples are provided as lists of possible descriptive and compact explanations for flexibility of adoption.

Metadata techniques


This key information can be hidden if metadata is missing.

Identifies any potential hazards (e.g., flashing elements, background sounds, and motion simulation) that could afflict physiologically sensitive users.

Unlike other accessibility properties, the presence of hazards can be expressed either positively or negatively. This is because users search for content that is safe for them as well as want to know when content is potentially dangerous to them.

The hazards property vocabulary includes a value of unknown, which means the content creator of the metadata explicitly acknowledges that the resource has not been checked for hazards. This is different than providing no metadata for this property which does not carry any meaning.


The examples are provided as lists of possible descriptive and compact explanations for flexibility of adoption.

Metadata techniques

Accessibility summary

This key information can be hidden if metadata is missing.

The accessibility summary was intended (in EPUB Accessibility 1.0) to describe in human-readable prose the accessibility features present in the publication as well as any shortcomings. From EPUB Accessibility version 1.1 the accessibility summary became a human-readable summary of the accessibility that complements, but does not duplicate, the other discoverability metadata.

It is a free-form field that allows authors to add additional information to the accessible properties of the resource.

Due to its nature, no specific processing of the content is required; it is sufficient to extract the text from the metadata and display it to end users.


Metadata techniques

Additional accessibility information

This key information can be hidden if metadata is missing.

This section lists additional metadata categories that can help users better understand the accessibility characteristics of digital publications. These are for metadata that do not fit into the other categories or are rarely used in trade publishing.

Additional accessibility information includes a wide range of information related to the publication's content. Therefore, the features are grouped so that the presentation is more understandable to end users.


For information on any structuring aids that facilitate use of a resource (e.g., ARIA).


For information on provisions in the content that enable reading in alternative access modes (e.g., closed captions, ruby annotations, sign language, transcript).


For information on ways that the content has been enhanced for improved auditory or visual clarity (e.g., high contrast display).


For information on content that is available in tactile form (e.g., tactile content, tactile graphic, tactile objects).


For information on specific types of content present in the digital publication (e.g., text on visual, music on visual).


For information that does not fall into one of the preceding categories (e.g., timing control and color dependent).


Metadata techniques

Discovering accessible content

The guidelines for presenting accessibility metadata detailed in this document are intended to improve the user experience when readers browse the catalogue entry for a publication. However, accessibility metadata also has a vital role to play in helping readers discover publications that are accessible to them.

Publication providers, such as vendors and libraries create searching and filtering tools that interpret accessibility metadata to aid in discovery. The set and variety of filters depend on the public they address and the type of book they propose.

User feedback indicates that in the absence of specific accessibility filters, they find product details like file format and protection measures (e.g., digital rights management) crucial information in determining usability.

Taking into consideration those realities, the following sections propose a minimum and an extension set for filtering options. Mostly any specific information could be added if considered of use for the public of the platform.

Minimum filtering set

Reading systems, commerce, and distribution platforms will typically have specific filtering options; having uniformity for key aspects and providing guidance for a standardized approach can help the discovery process for users searching for relevant titles. Accomplishing this, however, should not prevent users with specific reading needs from finding books they are looking for. To achieve this goal, it is recommended that all platforms present two minimum capabilities, centered around the ways of consuming the content. These are:

  1. Titles that support nonvisual reading
  2. Titles that support visual adjustments

Of note, only the positive values should be used.

Extended filtering set

In specific domains, the addition of other options will become important to help users find content that responds to a particular need or scenarios. Each domain case would uniquely drive the selection of appropriate items. Some examples of these domains (not exclusive) are:


In these guidelines, we have used simple language to communicate the meaning of the metadata values. Many people have contributed to the development of the words and phrases we have selected. We intend to provide a mechanism for the publishing community to provide translations that localizes the strings for equally effective communication in many languages. We understand that simply translating the strings is not enough; the subtle meaning of the words and phrases of accessibility concepts must be localized for maximum understanding.

For users seeking books, a seamless user experience is essential to avoid adding cognitive load to the already complex task of understanding the included features and accessing the book.

The wording is part of the UX and similarities of wordings in language areas are as crucial as the organization and categorization of the information.

The wording proposed in this guide has been widely discussed by a large group representing different actors of the English-speaking geographies. It has been improved after proof-of-concept implementations and reviewed by panels of testers.

To agree on linguistic areas wordings the actors should follow a localization framework. The UX guide translation webpage will propose such framework and list translations with contextualization of the localization process.


These guidelines provide a general framework and make suggestions on the display of accessibility metadata. It is not a normative description of what must be done. It is instructive to provide examples of implementations from the community.

We are collecting information on companies and organizations that wish to possibly commit examples of their implementation. Please visit the GitHub issue to review companies and organizations that have volunteered. Please put your company name, your name and your contact information to possibly volunteer an implementation.

Linked below are static pages that show real-life implementations. We have captured these examples from organization's websites that have agreed to allow us to showcase the work they have done to display accessibility metadata.

Links TBD