This Wiki page is edited by participants of the HTML Accessibility Task Force. It does not necessarily represent consensus and it may have incorrect information or information that is not supported by other Task Force participants, WAI, or W3C. It may also have some very useful information.
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Provide a CAPTCHA example that is in accord with WCAG 2 or Defer to "HTML5: Techniques for providing useful text alternatives"
Provide a text alternative for the CAPTCHA example
The "Images whose contents are not known" section of the HTML5 spec contains the following CAPTCHA example.
Sometimes the entire point of the image is that a textual description is not available, and the user is to provide the description. For instance, the point of a CAPTCHA image is to see if the user can literally read the graphic. Here is one way to mark up a CAPTCHA (note the title attribute):
<p><label>What does this image say? <img src="captcha.cgi?id=8934" title="CAPTCHA"> <input type=text name=captcha></label> (If you cannot see the image, you can use an <a href="?audio">audio</a> test instead.)</p>
A text alternative for this example is missing. Please provide one that is in line with WCAG 2 or defer to "HTML5: Techniques for providing useful text alternatives": http://dev.w3.org/html5/alt-techniques/ as a CAPTCHA example will be added there. http://www.w3.org/Bugs/Public/show_bug.cgi?id=9169
HTML5 Issue and Change Proposal
This is associated with HTML TRACKER ISSUE-31:
Change Proposal - Replace img Guidance for Conformance Checkers: