With version 3.4, the @w3c Publishing Maintenance #WorkingGroup is planning to enhance #EPUB3.3 by standardizing Webtoons, annotations, and #accessibility.
New technical features are added to: EPUB 3.4: https://www.w3.org/TR/epub-34/
EPUB Reading Systems 3.4: https://www.w3.org/TR/epub-rs-34/
EPUB Accessibility 1.1.1: https://www.w3.org/TR/epub-a11y-111/
Feedback welcome: https://github.com/w3c/epub-specs/