Does aria-label trigger presentation role conflict?

[WilcoFiers]

In ARIA 1.2 the concept of prohibited properties and states was introduced. This included prohibiting aria-label and aria-labelledby on presentation and none. Reading the description of global attributes then seems to suggest (but not explicitly state) that prohibited props are not global.

6.5 Global States and Properties

... The following global states and properties are supported by all roles and by all base markup elements unless otherwise prohibited...

• aria-label (Except where prohibited)

If aria-label is no longer considered a global property for presentation, that means using it wouldn't cause presentational role conflict to occur, and so some browsers have started ignoring aria-label when used on presentational elements (implicit and explicit):

<img src="img1.png" alt="" aria-label="Hello world" />
<img src="img2.png" role="none" aria-label="Hello world" />

Browser	img1	img2
Firefox	Included	Included
Chrome	Included	Skipped
Safari	Skipped	Included

It's not clear whether or not this was the intended behavior for prohibited properties. In either case it would be good for the presentational role conflict resolution to clarify what should happen with prohibited attributes.

This issue came up in migrating ACT rules to WAI-ARIA 1.2, and is one of the outstanding questions we have for updating our Element marked as decorative is not exposed rule.

[scottaohara]

can see why you'd come away with that interpretation, this needs to be more clear. But the attributes are still global and 'prohibited' is presently an author requirement, not one for UA.

This issue should be considered / will likely be covered by what is needed to resolve #1288 / #1474 (and many more issues related to the topic of the presentational conflict resolution).

[jnurthen]

Tests created by #1938