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 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.
Introduction
Background
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 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 information 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 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.
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.
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:
File format (EPUB, PDF, MP3, Audiobook, etc.)
Protection measure or lack thereof
Date of publication
Name of the publishing house
Main language of the content
Why this information is important for accessibility
The file format gives a strong indication of accessibility: an MP3 format audiobook will be less
structured than an Audiobook; a PDF does not allow for typography modification, etc.
The protection measure may block assistive technologies such as screen readers. In addition, many
specific reading devices such as DAISY readers or Braille notepads are not equipped to read
encrypted files.
The publication date gives an indication of when the files were produced. A book published before
2011 will probably be an EPUB2 file including poor semantics, and a book published in 2022 will be
more likely to be correctly structured and benefit from strong semantics.
The name of the publishing house can highlight the efforts it has made in terms of accessibility.
The main language of the content enables readers to be confident that they will be able to read
with their Assistive Technology that uses synthesized voice or the corresponding Braille table for
the language.
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).
Examples
The examples are provided as lists of possible descriptive and compact explanations for
flexibility of adoption.
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.
Examples
The examples are provided as lists of possible descriptive and compact explanations for
flexibility of adoption.
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 a publication identifies that there are accessibility problems, the statement should indicate that
there are known accessibility limitations. 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 claims to meet accepted accessibility standards.
The publication contains a conformance claim that it meets the EPUB Accessibility and
WCAG 2 Level AA standard.
This publication claims to meet minimum accessibility standards.
The publication contains a conformance claim that it meets the EPUB Accessibility and
WCAG 2 Level A 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 claim that is not to the EPUB Accessibility
standard.
This publication is known to have accessibility limitations.
The publication does not claim to meet the requirements of EPUB Accessibility or WCAG 2
Level A.
The accessibility of this publication is unknown.
The publication does not include a conformance claim.
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. If the publication has
been reviewed and there are known accessibility limitations, then this information can also
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.
Reason why the publication does not claim to meet the standards
For some jurisdictions, it may be important to indicate why a publication is not compliant
with the standards, such as if the company is too small and therefore not required to, or if
the cost to produce the accessible version is too high. Showing this information may be
important if required by local legislation, otherwise it can be omitted.
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 and fourth show 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
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.
Examples
The examples are provided as lists of possible descriptive and compact explanations for
flexibility of adoption.
This key information can be hidden if metadata is missing.
Identifies the navigation features included in the publication.
Offering different ways to navigate digital publications (table of contents, index, etc.) is
important to allow the user to easily access each part of the content. These features are both
essential for accessibility and very important for all users reading publications. Therefore,
clearly communicating to the user what navigation features are available in the publication is
important to enable proper selection.
Note that the Web Content Accessibility Guidelines (WCAG) 2.1 standard requires that more than one
way is available to locate a Web page within a set of Web pages (Success Criterion 2.4.5 Multiple
Ways).
Examples
The examples are provided as descriptive and compact explanations for flexibility of
adoption.
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.
Examples
The examples are provided as lists of possible descriptive and compact explanations for
flexibility of adoption.
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.
Examples
The examples are provided as lists of possible descriptive and compact explanations for
flexibility of adoption.
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.
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).
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).
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:
Titles that support nonvisual reading
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 an academic context, the presence of printed page numbers may be crucial to make sure the
reader will be able to find or make a reference.
In a technical or scientific context, the information about ways provided to access complex
contents like Charts, Diagrams, and Formulas would have a strong importance to know if
accessibility markup were present.
In markets where compliance to legislation is required, understanding conformity information
becomes mandatory.
Platforms dedicated to selling children's books and interactive content may want to allow users
to select books with no hazards or inform them about the presence of pre-recorded audio.
Localization
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.
Implementations
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.
