a href

Semantics

Semantic elements and attributes improve communication. For details please consult the semantics document.

The semantics of an href does not provide a clear, direct, explicit, and strong semantic for a long description.

Not Programmatic Determinable

Programmatic determinability aids accessibility.

A normal link below or near an image or in another part of the document is not programmatically determinable. Without programmatically determinability no explicit relationship exists to indicate that a long description has anything to do with an image.

Impossible for One Link to Have Two Destinations

The fact is a href only works on a limited subset of use cases as it is impossible for one link to take a user to two locations. An href is not programmatically determinable when an image already has a link, which is mapped to go to another page or a larger image.

Expecting all <img> elements on the web that need long descriptions not to have a parent <a> element mapped to a different task unrelated to a long description is unrealistic, i.e., a thumbnail <img> that links to a larger .jpg as evidenced by sites such as the National Institute of Dental and Craniofacial Research.

For example, if an image already has a link that takes the user to another page (i.e., a logo image that links to a home page, one cartoon in a series of cartoon images that links to the next comic strip page, a thumbnail image that links to a larger version of an image, etc.), it is impractical and most times nonsensical for the destination page to shoehorn in a long description. It would provide a confusing and inferior user experience.

Removing the possibility for direct, dual, programmatic access to both a long description via longdesc and a separate a href on an <img> element would be (a) needless authoring impediment, (b) a step backwards for HTML, and (c) a barrier to providing accessible content. Including longdesc in HTML5 affords authors a way to provide both an a href as well as an accessible programmatically determinable long description.

Forces a Visual Encumbrance

An href forces a visual encumbrance on sighted users unless additional code (in the form of CSS or hidden) were added in order to hide the visual indicator. Please refer to the Cascading Style Sheets and hidden documents for details of why using these techniques is a bad idea.

No Evidence of Improvement

No evidence has been presented that an href produces more accessible content for long descriptions.