The following is a Change Proposal for content in the Section 4.8.1 the img element to:
- Implement one aspect of the WAI CG Consensus Resolutions on Text alternatives in HTML 5
- Resolve ISSUE-80: Document conformance and device dependent display of title attribute content.
Editor: Steve Faulkner (email@example.com)
Date: December 3, 2009. (updated 14 April 2010).
Please address feedback to the HTML Working Group mailing list (firstname.lastname@example.org).
Removal of advice or requirements relating to the use of the title attribute in cases where a text alternative is not available.
For modification of sub section 18.104.22.168.14 Guidance for conformance checkers of section [4.8.1 The img element http://dev.w3.org/html5/spec/text-level-semantics.html#the-img-element] and associated text under "Images whose contents are not known":
- To reflect the unsuitability of title attribute content to act as a caption when a text alternative is not available, as the content is not displayed to the user unless they can use a mouse and they know the content is there. Refer to Issue 80 for more detail.
- The title attribute has been around for over 10 years and it has never been implemented in a way that would make it a suitable substitute for alt attribute content, and there is no sign from implementors that this situation will change.
- Suggesting that the title is an adequate substitute may encourage authors to not provide a text alternative using the alt attribute as conformance checkers will not flag the abscence of the alt attribute as an issue.
- Encouraging use of the title attribute before it is implemented in an accessible way does a disservice to users with disabilities.
- The specification forbids user agents from displaying title attribute content in the same way it displays alt attribute content:
"The alt attribute does not represent advisory information. User agents must not present the contents of the alt attribute in the same way as content of the title attribute."
This constraint makes it even less likely that at some point in the future a criitical mass of browsers will implement title attribute such that its content will be displayed in a manner that provides equivalent access to the content for all users.
Removal of the following (under "Images whose contents are not known"):
<li>The <code title=attr-title><a href="dom.html#the-title-attribute">title</a></code> attribute is present and has a non-empty value.</li>
and (under "22.214.171.124.14 Guidance for conformance checkers"):
<li>The <codetitle=attr-title><a href="dom.html#the-title-attribute">title</a></code> attribute is
present and has a non-empty value (as <a href="#unknown-images">described above</a>).</li>
- The removal of these conditions pertaining to the presence of the title attribute will reflect the reality that putting content in the title attribute is not a good alternative to use of the alt attribute as the content of the title attribute is not available to users if images are not displayed. The removal of this step also reflects the the consensus decision of the W3C WAI groups on this subject.
Conformance Classes Changes
The presence of a title attribute on an img without an alt attribute will no longer be conforming.
- HTML5 4.8.2 The img element
- WAI CG Consensus Resolutions on Text alternatives in HTML 5
- Address ISSUE-80 Document conformance and device dependent display of title attribute content
- Address ISSUE-31 What to do when a reasonable text equivalent is unknown/unavailable?
- Omitting Text Alternatives on <img>