Included objects have an appropriate fallback.

Some digital books contain particular objects such as interactive javascript elements (form, map, etc.) which may be impossible to consult in certain contexts. An alternative allows access to their content.

Objectives

• Provide access to information for users whose reading device does not support the inclusion of objects or the technologies used in the included objects.
• Facilitate the exploitation of this content by robots.
• Improve the accessibility of content to people with disabilities.
• Improve the consideration of content by search engines and indexing tools

Implementation

Use intrinsic fallback mechanisms (such as those available for the [html] object and canvas elements) or, when an intrinsic fallback is not applicable, by using a manifest-level fallback. Fallback chains are created using the fallback attribute on manifest item elements. This attribute references the ID [xml] of another manifest item that is a fallback for the current item.

Control

Validation

• Needs to be human verified.