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Understanding Accessibility Features

Accessibility metadata can be provided by publishers and libraries in the book's metadata records, whether it's ONIX, MARC, or in the EPUB itself ( If provided, NNELS will display this accessibility information to readers so that they can search for and download the books that best meet their needs.

The accessibility features that NNELS displays include: 

  • Customizable display: "Customizable display" means the book can be visually customized or modified by the reader. Readers can adjust font size, font type, contrast, etc.
  • Described images: "Described images" means the book has all of its images described using alternative text or long descriptions, where required.
  • Described math: "Described math" means the book has math equations that have been described accessibly using MathML, or plain language description.
  • Heading navigation: "Heading navigation" means all headings in the book are properly marked up (h1, h2, h3, etc.) so that readers can navigate by headings.
  • Print page numbers: "Print page numbers" means that the book contains a page list. The page list is a navigation aid that provides a list of links to static print page break locations (i.e. that do not change based on screen size or when the display is transformed).
  • Read aloud: "Read aloud" means the book contains full-text synchronized with human audio.
  • Table of contents navigation: "Table of contents navigation" means the book contains a table of contents (in the EPUB navigation document, i.e. the toc nav) for navigating the major sections of the work. It should include at least all the top-level headings.
  • None provided: This indicates that the publisher did not provide any accessibility metadata. It does not indicate that the book is inaccessible.