normative differences in ARIA requirements between HTML5 and the WHATWG spec

Hi Mike,

I know you are working on the conformance rules for ARIA in HTML5 at the

There is now a difference between the conformance requirments for use of
ARIA in the W3C HTML5 specification and the WHATWG spec.

The WHATWG document[1] contains this additional restriction:

"Authors must not set the ARIA role and aria-* attributes to values that
match the default implicit ARIA semantics defined in the following two

so the example below is conforming under the w3c html5 spec but not under
the whatwg

<button role=button aria-pressed=true>play</button>

note: in cases where aria-* attributes are specific to a particular role(s)
it is required (as implemented) to explicitly add the role even when the
default implied role is the same.

Are you going to be implementing the conformance rules as per HTML5 or as
per the WHATWG spec?

with regards

Steve Faulkner
Technical Director - TPG | |
HTML5: Techniques for providing useful text alternatives -
Web Accessibility Toolbar -

Received on Friday, 6 May 2011 20:38:55 UTC