H45: Using longdesc

The objective of this technique is to provide information in a file designated by the longdesc attribute when a short text alternative does not adequately convey the function or information provided in the image. The longdesc attribute is a URI, the target of which contains a long description of the non-text content.

• G73: Providing a long description in another location with a link to it that is immediately adjacent to the non-text content
• G74: Providing a long description in text near the non-text content, with a reference to the location of the long description in the short description
• G92: Providing long description for non-text content that serves the same purpose and presents the same information
• G94: Providing short text alternative for non-text content that serves the same purpose and presents the same information as the non-text content

Procedure

1. Check that the img element has a longdesc attribute.

2. Check that the value of the longdesc attribute is a valid URI of an existing resource.

3. Check that the content at the target of that URI contains a long description describing the original non-text content associated with it.

Expected Results

• #1 through #3 are all true

If this is a sufficient technique for a success criterion, failing this test procedure does not necessarily mean that the success criterion has not been satisfied in some other way, only that this technique has not been successfully implemented and can not be used to claim conformance.