On Wed, Nov 4, 2009 at 5:57 AM, Markus Ernst <[email protected]> wrote: > While experimenting with the validator (at validator.w3.org), I found that > it does actually not complain about <h1 src="whatever.gif">. Thus, Tab's > example would be perfectly valid. The validator even seems to accept any > custom attribute name on any element - this is said to be valid HTML5: > > . . . > > Is this a mistake in the validator, due to its experimental state, or is > there something missing in the spec?
A mistake in the validator. http://validator.nu/ gives the correct answer: it's invalid. You need to prefix custom attributes with "data-".
