Summary

The epub:type attribute can enhance the user experience in EPUB reading systems but does not improve the accessibility in assistive technologies.

Techniques

Note

No other uses of epub:type are known to provide user enhancements at this time.

Examples

Common note semantics
Footnote and reference
<p>lorum ipsum.<a epub:type="noteref" href="#fn01">1</a></p>
<aside epub:type="footnote">
   …
</aside>
Endnote and reference
<p>lorum ipsum.<a epub:type="noteref" href="#en01">1</a></p>
<aside epub:type="endnote">
   …
</aside>
Endnotes section
<section epub:type="endnotes">
   <h1>Endnotes</h1>
   
   <section>
     <h2>Chapter 1</h2>
     <aside epub:type="endnote">
       …
     </aside>
     …
   </section>
   …
</section>

Explanation

The enabling of specialized behaviors, such as the opening of footnotes, requires that content be properly identified for reading systems.

The epub:type attribute can be attached to any element in the body of a document to add additional semantics. It accepts any of the terms defined in the EPUB Structural Semantics Vocabulary, but the attribute has limited adoption outside of pop-up footnotes.

Note that only certain semantics make sense to use on any given tag. Marking an aside element as a footnote is appropriate, for example, but marking a section as a footnote not as much. The Structural Semantics Vocabulary lists the common element(s) each semantic is intended to be used in conjunction with to facilitate this process (although exceptions to the rule may arise).

Comparison to ARIA roles

The epub:type attribute only facilitates user agent behaviors like pop-up notes. It was hoped it would bridge the need for publisher workflow semantics with accessibility, but did not succeed. It does not improve the accessibility of publications on its own.

The attribute may still be useful for internal workflows as a means of generating ARIA roles, but in these cases the requirements of the ARIA specification must be closely followed. The use of roles is much more restrictive than epub:type.

It is also possible to use both the epub:type and role attributes where both accessibility and enhanced user agent behaviors overlap.

Refer to the EPUB Type to ARIA Role Authoring Guide for a list of bad practices to avoid when switching from the epub:type to the ARIA role attribute.

Related Links