Introduction to ONIX Metadata for Ebooks (and the Supply Chain)
This resource discusses the importance of ONIX accessibility metadata, and shares an example of the accessibility section of an ONIX file.
Once your ebook has been created, it is time to do a quality assurance check for accessibility. This resource contains both simplified and advanced checklists to help you review your ebooks.
Subject(s):
Ebook Production
Resource Type(s):
Checklist
Audience:
Introduction
Before reading this, you might want to read:
Downloadable version of the checklists are at the bottom of this page.
When you perform Quality Assurance for an EPUB, whether it was created by a third-party conversion company or by someone in-house, it is important to review the completed books for accessibility. This will help ensure that all required accessibility features have been included, and the book meets your own standards. For front-list titles, you’ll likely want to review each one; for backlist remediation projects, you may wish to review a percentage instead (if numerous titles are done in a bulk project).
If you are working with a Global Certified Accessible conversion vendor, you can feel more confident that the items in the following checklist are met. Nevertheless, developing a workflow that includes checking for accessibility, regardless of the source of the ebook, is a great idea!
Whether your book is in fixed-layout format or reflowable, it needs to meet most of the same requirements. The only exception is that users will not be able to adjust and customize the appearance of a fixed layout book. This is something that should be noted in your accessibilitySummary metadata, but it is understood that this is a limitation of fixed layout. Everything else applies!
This checklist covers the basics — if you can say yes to each one, then your book meets the Web Content Accessibility Guidelines, Level AA, and the EPUB Accessibility Specification. (Downloadable version below.)
Feature | Required/Recommended |
---|---|
Add alt-text for all non-decorative images | Required |
Ensure that decorative images are properly marked up | Recommended |
Ensure that the book’s content is in the correct reading sequence | Required |
Ensure that headings are marked up as HTML headings, and cascade in the correct order | Required |
Update the <title> elements for each document, so that they are descriptive | Required |
Ensure that links have useful link text | Required |
Ensure that internal links (like links from the table of contents, of between foot/endnotes and the text) are working | Required |
Ensure that if there are footnotes or endnotes, the user can easily return to the text from the note (either by linking the note number, or by adding a link with text like “Return to text”) | Required |
Add language declarations to the OPF <package> element, and to the <html> element for each document | Required |
Mark up language shifts where appropriate | Required |
Ensure that accessibility metadata is included | Required |
Ensure that all text styling and spacing comes from the CSS — no inline styling should be used | Required |
Ensure that the book opens to the cover page | Recommended |
Use ARIA roles | Recommended |
Set the title page as text, if possible — if not, be sure to add alt-text | Recommended (Note: if the title page is set as an image, alt-text is required) |
If possible, add page navigation and a page list | Required |
Mark context breaks up with an <hr/> element | Recommended |
Ensure that all text and background (even images of text) meet colour contrast requirements | Required |
Ensure that <b> , <i> , <strong> , and <em> are used appropriately | Rccommended |
If you are a little more comfortable with EPUB, and want to be confident that you are going above and beyond when it comes to including accessibility features, use this checklist. It includes some additional features, and also breaks some features down. (Downloadable version below.)
Category | Question | Required/Recommended |
---|---|---|
EPUB Version | Is the book in EPUB 3 format? | Recommended |
Is the book reflowable (not fixed layout)? | Recommended | |
If the book is in fixed layout, does it need to be? (i.e., is it an image-heavy publication?) | Required | |
Language | Does the element of the OPF file have an xml:lang attribute that specifies the language of the metadata? | Required |
Is the <dc:language> tag listed in the metadata section of the OPF file, with the correct language of the book? | Required | |
Is the language declared in the <html> tag at the top of each content document, with both the lang and xml:lang attributes? | Required | |
Are passages in a secondary language marked up with lang and xml:lang attributes? | Recommended | |
Accessibility metadata | Accessibility metadata | Required |
Image descriptions | If the cover page is set as an image, is it described? | Required |
If the title page is set as an image, is the textual information included in the alt-text? | Required | |
Are logos described? | Required | |
Are all other non-decorative images described? | Required | |
Are decorative images coded with an empty alt attribute and an ARIA role of "presentation"? | Required | |
Colour contrast | Is there sufficient colour contrast between text and background? (Note that this also applies to images of text) | Required |
Page navigation | Does the book have page navigation? | Required |
Is a page list included in the navigation file? | Required | |
If the page numbering is based on a print edition, is the pagination source included in the OPF file? | Required | |
Are page breaks coded with proper markup so they can be read by assistive technology? | Required | |
Document titles | Do the <title> tags of content documents accurately describe their content? | Required |
Headings | Are HTML headings (<h1> to <h6> ) used for every section that has a heading (like parts, chapters, etc.)? | Required |
Are <section> tags with ARIA roles or aria-labels used for sections without headings (like cover, title page, etc.)? | Required | |
Is a single heading used for each section, even if it breaks over two lines? | Required | |
Have all heading tags been used correctly? (i.e., heading tags only mark up headings, and are not used to force text to look a certain way visually) | Required | |
Is heading hierarchy correct? | Required | |
Sections | Are <section> tags used for main sections of the book? | Recommended |
Navigation | Can all documents listed in the spine section of the OPF file be reached from the navigation pane? | Required |
Is the list of sections in the navigation file organized hierarchically, using nested lists if applicable? | Required | |
If the book has a table of contents in the body matter, are entries linked? | Recommended | |
If the book has a table of contents in the body matter, are entries organized hierarchically in a list, similar to the navigation file? | Recommended | |
Tables | If there are tables, are they marked up correctly? | Required |
If there are images of tables, is an HTML version available elsewhere, such as a long description? | Required | |
If tables have captions at the beginning, has a <caption> tag been used to associate the caption with the table? | Recommended | |
Does the book use CSS for laying out text, instead of forcing? | Required | |
Links | If the book includes URLs in the text, are they marked up as links? | Required |
If the book includes URLs in the text, are they marked up as links? | Required | |
Is link text descriptive and concise? | Required | |
Footnotes and endnotes | Are footnote and endnote references linked to their corresponding notes? | Required |
Do footnotes and endnotes have a link to return to their note reference in the text? | Required | |
If there are footnotes, are they marked up using <aside> tags? | Recommended |
|
Block quotations | Are block quotations marked up with <blockquote> tags? | Recommended |
Emphasis | Is emphasized content marked up with proper semantic elements (e.g., <em> , <i> , <b> , <strong> ) | Recommended |
Drop caps | If there are drop caps, does the code in content documents avoid splitting words with <span> tags? | Recommended |
Capitalization | If there Is content in all capital letters, is it marked up correctly (i.e., using the font-variant:small-caps in the CSS)? | Recommended |
Text styling | Does all styling come from CSS? (There should be no inline styling) | Required |
Sidebars | If there are sidebars, are they marked up with <aside> tags? | Required |
Figures | If there is content with captions (such as illustrations, photographs, etc.), is it the image marked up with a <figure> element, and the caption with <figcption> ? | Recommended |
Lists | Are lists used to mark up sections like table of contents, bibliographies, and indexes? | Recommended |
If there are obvious lists of items in the body matter of the book, are they marked up as lists, and not paragraphs? | Recommended | |
Context breaks | If there are context breaks, are they marked up with <hr/> elements? | Recommended |
Media overlays | If the book includes media overlays, are they synchronized with the text? | Required |
If the book includes media overlays, are skippable and escapable structures marked up? | Required |
Both the simplified and advanced checklists are available at this link.
This specification discusses discovery and accessibility of EPUB publications. Discovery relates to accessibility metadata. Accessibility includes guidelines in WCAG 2.0 and some additional items on page navigation and media overlays. The specification also discusses how to indicate conformance, information about optimized publications for specific use cases such as audiobooks, and a short section on distribution considerations.