Updated Candidate Recommendations for EPUB 3.3, EPUB Reading Systems 3.3, EPUB Accessibility 1.1

The EPUB 3 Working Group invites implementations of three revised Candidate Recommendations:

  • EPUB 3.3 defines the authoring requirements for EPUB publications and represents the third major revision of the standard.
  • EPUB Reading Systems 3.3 defines the conformance requirements for EPUB 3 reading systems — the user agents that render EPUB publications.
  • EPUB Accessibility 1.1 specifies content conformance requirements for verifying the accessibility of EPUB® Publications. It also specifies accessibility metadata requirements for the discoverability of EPUB publications.

EPUB® 3 defines a distribution and interchange format for digital publications and documents. The EPUB format provides a means of representing, packaging, and encoding structured and semantically enhanced web content — including HTML, CSS, SVG, and other resources — for distribution in a single-file container.

Please send comments by 21 March 2023.