* [Display Techniques for EPUB Accessibility Metadata 2.1](https://w3c.github.io/publ-a11y/a11y-meta-display-guide/2.1/draft/techniques/epub-metadata/)
* [Display Techniques for ONIX Accessibility Metadata 2.1](https://w3c.github.io/publ-a11y/a11y-meta-display-guide/2.1/draft/techniques/onix-metadata/)