HTML4.01 Strict ARIA Doctype for Validation via W3C Validator

Question

Is there any <!doctype> for "HTML 4.01 Strict Markup + ARIA"?

Also am currently having HTML 4.01 Strict <!DOCTYPE>, I obviously get an error while validating my page with the W3C Validator.

Is there any solution to this problem?

Also when I use the Accessibilty Toolbar, I get the following error pointing to the line after the closing HTML tag:

Line 256, Column 1: character data is not allowed here
Content-Disposition: form-data; name="charset"

You have used character data somewhere it is not permitted to appear. Mistakes that can cause this error include:

• putting text directly in the body of the document without wrapping it in a container element (such as a <p>aragraph</p>), or

• forgetting to quote an attribute value (where characters such as "%" and "/" are common, but cannot appear without surrounding quotes), or

• using XHTML-style self-closing tags (such as <meta ... />) in HTML 4.01 or earlier. To fix, remove the extra slash ('/') character. For more information about the reasons for this, see Empty elements in SGML, HTML, XML, and XHTML.

Answer 1

There is no published DTD for HTML 4.01 + ARIA. It would be possible to write one, if only there were a stable, exact document that specifies the allowed ARIA attributes and the HTML 4.01 elements on which they may be used. Using WAI-ARIA in HTML is still a WD only, and calls itself “a practical guide”. And I’m not sure how it should be interpreted. I guess the simplest, and possibly the only realistic, approach would be to write a DTD that allows all ARIA attributes on all elements, with the same set of values for all elements, even thoughh this would violate many of the recommendations.

The other question seems to be unrelated, and should probably be asked as a separate question. And you should probably explain what accessibility toolbar you are referring to and what your HTML document contains.