Definition

No digital rights management or other content restriction protocols have been applied to the resource.

Examples

Example 1 — EPUB 3
<meta property="schema:accessibilityFeature">
   unlocked
</meta>
Example 2 — EPUB 2
<meta name="schema:accessibilityFeature"
      content="unlocked"/>
Example 3 — Audiobooks
"accessibilityFeature": ["unlocked"]

Explanation

The unlocked value is used to indicate that no digital rights management (DRM) or other content restriction protocols are applied to the content.

DRM schemes are often applied to digital publications to protect them from being copied, but these schemes, or the rights applied to the content, can sometimes interfere with the ability of assistive technologies to access or play back the text.

Note

It is often vendors who apply DRM schemes to publications before distributing them to users. As a result, before setting this value, authors need to ensure that the publication will not subsequently have DRM applied. The pubication has to be guaranteed to be unlocked after distribution.

Related Links