Accessibility Metadata Display Guide for Digital Publications 2.0

Draft Community Group Report

This version:
https://w3c.github.io/publ-a11y/a11y-meta-display-guide/2.0/guidelines/guidelines-draft-note-20241101.html
Latest published version:
https://www.w3.org/publishing/a11y/UX-Guide-metadata/principles/
Latest editor's draft:
https://w3c.github.io/publ-a11y/a11y-meta-display-guide/2.0/draft/guidelines/
Editors:
Charles LaPierre (Benetech)
Gregorio Pellegrino (Fondazione LIA)
Gautier Chomel (EDRLab )
George Kerscher (DAISY Consortium)
Feedback:
GitHub w3c/publ-a11y (pull requests, new issue, open issues)

Abstract

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. These guidelines 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.

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 Contributor License Agreement (CLA) there is a limited opt-out and other conditions apply. Learn more about W3C Community and Business Groups.

GitHub Issues are preferred for discussion of this specification.

1. Introduction

Reading a digital 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 e-book. 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 in any format.

The good news is more and more publishers are creating digital 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.

1.1 Terminology

There are several terms used in these guidelines that should be defined for clarity:

digital publication

The term digital publication is used in this document to refer to publications produced in any number of digital formats. Digital publications are not limited to books, but encompass any written, visual, or audio work distributed and read in digital form.

Some examples of digital publications include ebooks, audiobooks, manga, comic books, journals, digital textbooks, picture books, and children's picture books with accompanying audio. The formats they come in include EPUB, PDF, and Digital Talking Books (DTB).

reading system

All digital publications require a reading system to present the publication to the end user. Reading Systems may be Apps that run on a smart phone or tablet. There are Reading Systems which are applications that run on personal computers. There are also Reading Systems that are integrated in to dedicated devices devoted to a single purpose, for presenting a publication. There are even skills that run on smart speakers that can be considered Reading Systems.

electronic braille
refreshable braille

The terms "electronic braille" and "refreshable braille" can be used interchangeably, which denotes a device with pop-up pins to present the braille on a tactile screen. These devices can be used as a display attached to a personal computer, or they may be a self-contained multipurpose note taker with a refreshable braille display.

2. General overview

These guidelines help 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 guidelines and are encouraged to follow EPUB Accessibility 1.1 Conformance and Discoverability Requirements section and its techniques.

Note

This document presents high-level guidelines 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 – except for 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.

2.1 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.

2.2 Metadata processing overview

The following diagram depicts how these guidelines relate to the format-specific techniques in the process of receiving and displaying accessibility metadata.

Outline of the processing for EPUB, PDF, ONIX and MARC metadata. Description follows.
Note

Work on integrating PDF and MARC is ongoing. The diagram and text of this section will be updated in future versions as the related documents are finalized.

The diagram categorizes two ways that metadata accompanies a publication. In the first are digital publication formats that directly embed accessibility metadata (EPUB and PDF). In the second are external metadata record formats (ONIX and MARC) that accompany a digital publication as it moves through the supply chain.

In some cases, digital publication may include both internal and external metadata (e.g., an EPUB could have accessibility metadata in it package document and also be provided to a vendor with an ONIX record). In these cases, vendors and reading system developers determine for themselves which set of metadata they will use to display to users.

Note

This guide assumes the metadata is already in one of the formats described in the diagram, but depending on how the metadata is submitted it may need to be transformed (e.g. , if a vendor prefers to handle only ONIX metadata for display they would need to preprocess the metadata embedded in an EPUB or PDF file).

The process of transforming metadata is not it scope for this document nor is how to reconcile metadata when it is provided in multiple forms. The guide assumes any processing has already occurred. For information on mapping between formats, refer to the Accessibility Properties Crosswalk.

The next level of the diagram depicts the encoding standards expected for each format. This guide assumes that the metadata conforms to a recognized standard, otherwise it would be difficult to anticipate and process the incoming information for users:

Knowing how the metadata is encoded and how it is expressed, the next stage of processing is to use the algorithms defined in the respective techniques documents to discover and translate the information into human-readable statements. These documents are intended primarily for developers, to help them with the specific processing of the metadata markup grammars.

Finally, this document is shown at the last stage of processing, as it defines the purpose of each piece of metadata in more detail and prioritizes the display for readers.

2.3 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:

Note

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.

3. General 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 Accessibility Metadata Display Guide for Digital Publications) by parsing the metadata and using the appropriate Display Techniques document.

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

3.1 Why this information is important for accessibility

4. Key accessibility information

Introduction to key accessibility information

When focusing on the accessibility of any digital publication, three areas of key information come to mind:

This is why these guidelines recommend that three pieces of key information should always be displayed:

  1. Visual adjustments
  2. Supports nonvisual reading
  3. Conformance

The other five areas provide details about specific features or shortcomings in publications. It is expected that these other areas of key information will give people what they need to make an informed choice to read a particular e-book.

Note

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.

In this document are examples of important metadata that is expected to be in a wide range of publications. However, we do not have examples of all possible features that the metadata can express. The techniques have more values than are shown in the examples.

4.1 Visual adjustments

Note

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).

4.1.1 Examples

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

4.1.2 Display techniques for Visual adjustments support

Specific techniques for meeting this principle are defined in the following documents:

4.2 Supports nonvisual reading

Note

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 available to reading systems with text-to-speech or refreshable braille capabilities

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.

4.2.1 Examples

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

4.2.2 Display techniques for nonvisual reading support

Specific techniques for meeting this principle are defined in the following documents:

4.3 Conformance

Note

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 the publication does not include a conformance statement.

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.

4.3.1 Conformance statements

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

This publication exceeds accepted accessibility standards

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

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

The publication does not include a conformance statement

The conformance metadata is missing and conformity to a standard of this publication is unknown

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.

4.3.2 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.

4.3.3 Examples

Four 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 example shows a publication with unknown accessibility, and the final one shows that the conformance information is missing.

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

4.3.4 Display techniques for conformance support

Specific techniques for meeting this principle are defined in the following documents:

4.4 Pre-recorded audio

Note

This key information can be hidden if metadata is missing. Alternatively it can be stated that No information about pre-recorded audio is available.

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.

4.4.1 Examples

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

4.4.2 Display techniques for pre-recorded audio support

Specific techniques for meeting this principle are defined in the following documents:

4.6 Charts, diagrams, math, and formulas

Note

This key information can be hidden if metadata is missing. Alternatively it can be stated that accessibility of formulas, charts, math, and diagrams not identified as being accessible

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, math, charts, or graphs within the title, otherwise it can be hidden.

4.6.1 Examples

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

4.6.2 Display techniques for charts, diagrams, and formulas support

Specific techniques for meeting this principle are defined in the following documents:

4.7 Hazards

Note

This key information can be hidden if metadata is missing. Alternatively it can be stated that No information about possible hazards is available.

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.

4.7.1 Examples

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

4.7.2 Display techniques for hazards reporting

Specific techniques for meeting this principle are defined in the following documents:

4.8 Accessibility summary

Note

This key information can be hidden if metadata is missing. Alternatively it can be stated that No accessibility summary is available.

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.

4.8.1 Examples

4.8.2 Display techniques for accessibility summary support

Specific techniques for meeting this principle are defined in the following documents:

4.10 Additional accessibility information

Note

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.

Structure

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

Page breaks
The inclusion of page break markers from a print source allows users to identify where they are in a digital publication relative to its print equivalent.
Adaptation

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

Clarity

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

Tactile

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

Content

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

Other

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

4.10.1 Examples

Note
There are many features that may be present. Some of the features are listed in the examples. A complete list can be found in the techniques.

4.10.2 Display techniques for additional accessibility information

Specific techniques for meeting this principle are defined in the following documents:

5. 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.

5.1 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.

5.2 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:

6. Localization

An ebook can be purchased in any country without limited availability or additional delivery costs. Readers want consistent display of accessibility information, and that’s the primary role of the display guide. 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.

We understand that different countries or different target audience services may want to use specific language, and we have provided flexibility in the guide to accommodate this while maintaining a high level of understanding and similar quality to help users in a country find likewise information between two bookstores or libraries in the same language area. Simply translating the strings is not enough; the subtle meaning of the words and phrases of accessibility concepts must be localized for maximum understanding. Therefore, we intend to provide a mechanism for the publishing community to provide translations that localizes the strings for equally effective communication in many languages.

The Display guide localization strings page list translations with contextualization of the localization process.

The following subsections proposes a localization framework to help establishing linguistic areas wordings agreed between actors of the concerned geographical area.

6.1 Localization strategy

With the rapidly evolving landscape of accessible ebooks available, most concerned persons are discovering a new world. To ensure the information is widely spread and understood, the implication of local actors like NGOs libraries serving persons with disabilities and other local actors in the fight to end the book famine for readers with print disabilities is crucial and should be highlighted.

The localization of the display guide is a good opportunity to make known the rich accessibility features offered by modern formats like EPUB. Reversely, having a local project scale to write an understandable vocabulary to describe such features is a precious qualitative approach that will benefit to every player in the value chain.

To build a local project and facilitate feedback comparisons, you can use open source methodology, resources, and prototypes published by EDRLab for the original Signposting accessible digital books project that led to the initial Feedback letter (PDF) addressed in early 2022. And has already been used and adapted in various places.

In these projects, emphasis was placed on the implications for the end users. For instance, the French wording proposed by EDRLab resulted from a quantitative survey of different reader groups, carefully selected panels of individual observations, and an extended feedback process through a dedicated formula available on the 140 first implementation platforms.

Additionally, companies like VitalSource that need wide localization have offered to open-source their professional translation work, which has produced the needed quantity and that is better to use than nothing when no national project has issued a handcrafted vocabulary.

To reconcile both sources of provided localization materials, we propose a collection mechanism based on a detailed identification of the provenance. Because persons and organizations with different levels of technicality must be able to contribute, we accept both raw files via Pull requests and also propose a friendly localization user interface through GitLocalize.

6.2 How to contribute?

First let us know as soon as possible that you are working on a localization and wish to submit it. That allows us to prepare a placeholder for your work. This is not mandatory but we invite you to contact the group and participate to a regular call of the working group as those are open to anyone.

When you are ready to publish your work, two options are possible:

6.3 How to choose between localization files?

The first keys of each JSON files contains descriptive information about it, including

7. Implementations

Issue 268: Contact details of implementors UX-Guide
We are collecting information on companies and organizations that wish to possibly commit examples of their implementation. Please visit this GitHub issue to review companies and organizations that have put their name forward. To possibly volunteer an implementation, please put your company name, your name and your contact information.

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.

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

A. Acknowledgements

This section is non-normative.

The leadership and editing contributions of the following individuals were central to producing this guide:

The following members of the Publishing Community Group contributed to the development of this document:

B. References

B.1 Informative references

[epub-a11y-11]
EPUB Accessibility 1.1. George Kerscher; Matt Garrish; Charles LaPierre; Avneesh Singh; Gregorio Pellegrino. W3C. 17 October 2024. W3C Recommendation. URL: https://www.w3.org/TR/epub-a11y-11/
[epub-a11y-tech-11]
EPUB Accessibility Techniques 1.1. Matt Garrish; George Kerscher; Charles LaPierre; Gregorio Pellegrino; Avneesh Singh. W3C. 4 July 2024. W3C Working Group Note. URL: https://www.w3.org/TR/epub-a11y-tech-11/
[iso14289-1]
ISO 14289-1:2024: Document management applications — Electronic document file format enhancement for accessibility — Part 1: Use of ISO 32000-1 (PDF/UA-1). ISO. URL: https://www.iso.org/standard/82278.html
[iso14289-2]
ISO 14289-2:2024: Document management applications — Electronic document file format enhancement for accessibility — Part 2: Use of ISO 32000-2 (PDF/UA-2). ISO. URL: https://www.iso.org/standard/64599.html
[onix]
ONIX for Books 3.0. URL: https://www.editeur.org/8/ONIX/