Terse Descriptor Requirements and Normative Advice for HTML5, versions 2 & 2.5

NOTE: This page became obsolete on 4 March 2009; please consult the 4 March collaborative edits to the current proposal

Background

Since i STRONGLY believe that we need to focus our proposal squarely on alt and alt alternatives, alone, the one thing about GreggV's proposal which worries me is the conflation of the issues of terse and long descriptors: in my opinion -- for now -- we should be concentrating on methods of providing a terse descriptor, which is what the HTML WG has asked us for, before we open the can of worms that constitutes the mechanism for providing a detailed description of a static image.

Therefore, i offer the following as a "friendly-amendment" to GreggV's proposal on how to provide a normative means of programmatically designating an image as "presentation" or as an "image" so as to provide a terse textual equivalent for human consumption, and a machine processable flag that categorizes the role of the image and for validation purposes. Note that i have broken the proposal into 3 parts:

PROPOSAL, version 2 - GV+GJR

PROPOSAL GV+GJR, part 1

There are several ways of providing a terse text alternative for an image: using the alt attribute, aria-labelledby, or (if using FIGURE) LEGEND. One of these (alt, labelledby, or LEGEND) is required for validity. For guidance as to what constitutes a text alternative for the purpose of disability access consult WCAG 2.0.

PROPOSAL GV+GJR, part 2

That use of role = presentation as defined in ARIA 1.0 be added to the attribute list for the IMG element.

PROPOSAL GV+GJR, part 3

alt="" is valid ONLY when role = "presentation". An IMG without a role attribute is the equivalent of <IMG aria-role="image"> and REQUIRES the use of alt, labelledby, and/or LEGEND for validity. For guidance as to what constitutes a valid text alternative for the purpose of disability access consult WCAG 2.0.

Cautionary Note

Note: i have a knee-jerk reaction against the wording "what constitutes a valid text alternateive for the purpose of disability access, consult WCAG 2.0.", as alt text is not for disabled users only, but for anyone who cannot, for whatever reason, perceive or retrieve the image.

Proposal 2.5: GV+GJR+JR

That HTML5 validity require terse text alternatives, and that these be provided for non-text items using one of the HTML5 specified methods: (alt, labelledby, or LEGEND).
- A) For images (IMG: alt attribute or aria-labelledby can be used.
- B) For figures (FIGURE: alt attribute, aria-labelledby, or legend can be used; note that, for backwards compatibility, if an IMG is nested in a FIGURE element the content of the alt defined for the IMG MUST be the same as the content of the LEGEND. Authors are reminded that valid alt values are plain textual strings, while LEGEND can contain "rich", marked-up content;
- C) (others?)
That HTML5 state that "For guidance as to what constitutes a text alternative for the purpose of disability access authors should consult WCAG 2.0." (need a more specific pointer)
That the proper use of role = presentation be taken from ARIA 1.0.
That alt="" is valid ONLY when role = "presentation"
An IMG without a role attribute is the equivalent of <IMG aria-role="image"> and REQUIRES a terse text alternative. (consult list item #1, above)
Long text alternatives (to supplement terse text alternatives) are not required for validity (though they may be required by WCAG 2.0 for some types of non-text content).