Proposal for aria-detailstype

Online word processors often have a way of commenting or annotating a piece of text, that need to be exposed in accessibility APIs to assistive technologies. We need a way to markup comments and suggested changes in documents.

Here's the proposal:

When using aria-details, you can add an optional attribute aria-detailstype on the same element with one of the following values: commenting, suggesting, identifying, describing (default) — these are imported from the web annotations motivation vocabulary.

Possible values for future discussion:

• Additional values from the web annotations motivation vocabulary: editing, highlighting, linking, moderating, questioning, replying, tagging. These need use cases and examples.
• Additional custom types such as "breakpoint" needed for web-based code editors.
• Ideas from personalization spec.

Benefits: a new string attribute is very simple to implement in browsers, AAM's and AT's. Firefox probably already exposes the detailstype object attribute since it exposes any aria-foo attribute automatically.

Example in an editor:

(View source to see markup)