- From: John Foliot <foliot@wats.ca>
- Date: Tue, 5 Feb 2008 10:48:39 -0800
- To: "'Al Gilman'" <Alfred.S.Gilman@IEEE.org>, <wai-xtech@w3.org>
Apologies for top posting: Al, As an initial first response, I agree that the narrow response as proposed is a good one. I can support this position as well, although I agree with the minor edits suggested by David Poleman. JF ********* Al Gilman wrote: > <note > class="inDraft onProcess"> > > Earlier discussion on this point can be reviewed at > http://lists.w3.org/Archives/Public/wai-xtech/2007Oct/thread.html#msg44 > http://lists.w3.org/Archives/Public/wai-xtech/2007Nov/thread.html#msg12 > http://lists.w3.org/Archives/Public/wai-xtech/2007Nov/thread.html#msg47 > http://lists.w3.org/Archives/Public/wai-xtech/2007Nov/thread.html#msg50 > http://lists.w3.org/Archives/Public/wai-xtech/2008Feb/thread.html#msg0 > > Please comment on this on the XTECH list. > > PFWG could reach consensus on some variant of this > statement as early as Wednesday, 6 February or > it could take longer. > > I suggest that we should let this message go with the narrow topic of > "is @alt for critical content required?" and deal with the issues > such as > > - machine-recognizable associations between media objects and > mainline text > - new reserved values for @alt > > .. separately > > Al > > </note> > > The current TR draft for HTML5 contains the following language: > > <quote > cite="http://www.w3.org/TR/2008/WD-html5-20080122/#alt"> > A key part of the content that doesn't have an obvious textual > alternative > > In certain rare cases, the image is simply a critical part of the > content, and there might even be no alternative text available. This > could be the case, for instance, in a photo gallery, where a user has > uploaded 3000 photos from a vacation trip, without providing any > descriptions of the images. The images are the whole point of the > pages containing them. > > In such cases, the alt attribute may be omitted, but the alt > attribute should be included, with a useful value, if at all > possible. If an image is a key part of the content, the alt attribute > must not be specified with an empty value. > > </quote> > > <summary> > > 1. By the principles, HTML5 wants to support accessibility > > 2. By their charters, WAI groups (here WCAG) are the go-to experts > in matters of accessibility > > 3. WCAG requires @alt (WCAG1) or the function that in HTML4 > is provided by @alt (WCAG2) [editorial note -- add links] > > 4. By the principles, if it 'tain't broke, don't fix it. > > 5. Conclusion: barring the introduction of three fresh good reasons > for a change, the failure of the HTML5 draft to make @alt on <img> an > across-the-board requirement (even if sometimes it has the value of > "") is a bug. Or do you have reasons? > > </summary> > > <background> > > The applicable provision in the WCAG 1.0 Recommendation is Checkpoint > 1.1 > > <quote cite="http://www.w3.org/TR/WCAG10-TECHS/#tech-text-equivalent"> > > Provide a text equivalent for every non-text element (e.g., via > "alt", "longdesc", or in element content). This includes: images, > graphical representations of text (including symbols), image map > regions, animations (e.g., animated GIFs), applets and programmatic > objects, ascii art, frames, scripts, images used as list bullets, > spacers, graphical buttons, sounds (played with or without user > interaction), stand-alone audio files, audio tracks of video, and > video. [Priority 1] </quote> > > and in the WCAG 2.0 Last Call draft it is stated thus: > > <quote > cite="hhttp://www.w3.org/TR/WCAG20/#text-equiv-all"> > > 1.1.1 Non-text Content: All non-text content has a text alternative > that presents equivalent information, except for the situations > listed below. (Level A) How to Meet 1.1.1 Understanding 1.1.1 > > Controls, Input: If it is a control or accepts user input, then it > has a name that describes its purpose. (See also Guideline 4.1.) > > Media, Test, Sensory: If it is (1) synchronized media, (2) live audio- > only or live video-only content, (3) a test or exercise that must be > presented in non-text format, (4) primarily intended to create a > specific sensory experience, then text alternatives at least provide > descriptive identification of the non-text content , or (5) a media > alternative to text that is clearly labeled as such . (For > synchronized media, see also Guideline 1.2.) > > Note: Prerecorded audio-only and video-only files would be covered > under Success Criterion 1.1.1, which requires text alternatives that > present equivalent information. > > CAPTCHA: If it is to confirm that content is being accessed by a > person rather than a computer, then text alternatives that identify > and describe the purpose of the non-text content are provided, and > alternative forms of CAPTCHA using output modes for different types > of sensory perception are provided to accommodate different > disabilities. > > Decoration, Formatting, Invisible: If it is pure decoration, or used > only for visual formatting, or if it is not presented to users, then > it is implemented in a way that it can be ignored by assistive > technology. > > </quote> > </background> > > <finding> > > The language "In such cases, the alt attribute may be omitted," gives > the > appearance of creating a policy line that is inconsistent with WCAG, > whether 1.0 or 2.0. As such, this needs to be changed. HTML WG should > re-work the <img> element section to bring it into line as techniques > for implementing WCAG 2.0. We say 2.0 because of the strong > likelihood that WCAG 2.0 will precede HTML5 to Recommendation status. > > WCAG WG is chartered to set Accessibility guidelines and HTML WG is > not; so HTML5 should be careful to create features that support WCAG > and describe their use in ways that conform to WCAG. > > </finding> > > Al > /self (chair hat off)
Received on Tuesday, 5 February 2008 18:48:50 UTC