Understanding:Success Criterion 2.4.13: Page Break Navigation
Success Criterion 2.4.13 Page Break Navigation (Level A): For web content with page break locators, a mechanism is available to navigate to each locator.
Status
This understanding document is part of the draft WCAG 2.2 content. It may change or be removed before the final WCAG 2.2 is published.
Intent
The purpose of this success criterion is to allow people using assistive technology to find references to content based on the page break locators found in the default view or printed version of a publication.
Page numbering has long been a fundamental way to identify and communicate the location of written content. Page numbers are used constantly in references, footnotes, endnotes, and bibliographies. Particularly, they are critical in academic and learning environments.
Digital publishing has provided valuable access to content for people who are blind, have low vision, dyslexia or other cognitive disabilities. In order to consume the information the content may be adapted to use a different layout, or presented to them using assistive technology. If there is no clear way to find a specific page from the print version that was referenced by a professor in class, because the electronic version is zoomed-in and that paragraph is on page 145 of the user's version of the content, the user misses out on valuable and sometimes critical information to understanding the reference.
The scope of this criterion is web content which is part of a Web page. EPUB can fulfill this definition if it is available to read at a URI. The more common case that is in scope is an EPUB book converted to be read by a web browser.
In publishing, there can be many different editions of a work, e.g. a second edition or a paperback edition. There is a requirement (separate from accessibility) for metadata in digital publications like EPUB to identify the edition of the title of which this digital version represents. The page break locaters would be aligned with the specified edition.
Statically paginated formats (e.g., PDF) where the user agents include a mechanism to navigate by page typically meet this success criteria by default. The user agents for the EPUB format also typically provide the navigation mechanism if a page list is included. Web browsers do not have a standard page navigation mechanism, so for HTML content with page break locators it is the author responsibility to add that mechanism.
For a Page Break Locator to be a "programmatically determinable destination marker", it needs to have a role that identifies it as a page break, and a method of determining which page in a sequence it represents. This would not apply to an element which visually shows a page number, unless it also has a recognized role. H99: Provide page list navigation provides an example of a page break locator.
Benefits
- People who use a screenreader or adapt the display of the content will still be able to find their place and find references to content that are based on page numbers of the print or default version of the publication.
Examples
- An electronic publication (EPUB) document includes navigation to page number references that match the print version of the publication.
Related Resources
Resources are for information purposes only, no endorsement implied.
Techniques
Each numbered item in this section represents a technique or combination of techniques that the WCAG Working Group deems sufficient for meeting this Success Criterion. However, it is not necessary to use these particular techniques. For information on using other techniques, see Understanding Techniques for WCAG Success Criteria, particularly the "Other Techniques" section.