Item Number: Success Criterion 4.1.1
Part of Item:
Comment Type: TE
Comment (Including rationale for any proposed change):
In guideline 4.1.1 does "parsed unambiguosly" mean "well formed" or "valid"? The techniques seem to suggest that markup must be valid, though you would be hard pressed to find invalid code that disrupts any relatively recent screen reader's ability to read a Web unit. It takes severely broken markup to affect accessibility, or specific types of errors (such as broken table structures). While I am all for valid markup, it is *not* a requirement for accessibility in most cases, particularly at level 1. I can see this requirement at level 2 perhaps.
What would be appropriate here to have a well formed requirement at level 1, and valid at level 2. And still this really has to do with compatibility with future technologies, rather than affects on accessibility using current technologies.
We have reworded SC 4.1.1 to require that content can be parsed without error.
The working group looked at this topic carefully over an extended period of time and concluded that requiring strict adherence to all aspects of specifications does not necessarily result in an increase in accessibility. For example, it is possible to create invalid pages that present no accessibility barriers. It is also possible in certain situations to enhance accessibility through the use of markup that is not part of the specification.
The working group must work within its charter and only include things that directly affected accessibility. Some aspects of "use technologies according to specification" and validity do relate to accessibility. However, others do not. So requiring validity would take us beyond our charter. We do recommend it though and it is our #1 technique listed for conforming to SC 4.1.1.