Update aria-level on heading mapping to reflect UIA limitation

[aldietz]

We received a Chromium bug where aria-level values > 9 on heading do not work.

A commit in 2014 added this limitation due to UIA restrictions. UIA maps the aria-level on heading to the StyleId_Heading value, which is limited to 1 through 9.

Suggesting an update to the core-aam mapping for aria-level on heading to more clearly reflect this value range limitation or link to the StyleId_Heading documentation.

@joanmarie

[JAWS-test]

Related: FreedomScientific/standards-support#301 and w3c/aria-practices#1109

[JAWS-test]

https://w3c.github.io/aria-practices/#structural_roles restricts the use of aria-level to the values 1-6. I did not find this restriction in the ARIA specification itself. This should definitely be unified. If aria-level is really limited to 1-6 for headings, then this issue and the Chromium bug would be solved.

[aleventhal]

Agree to limit aria-level for heading — not for other roles that use aria-level.

…

On Tue, Jun 14, 2022 at 10:55 PM JAWS-test ***@***.***> wrote: https://w3c.github.io/aria-practices/#structural_roles restricts the use of aria-level to the values 1-6. I did not find this restriction in the ARIA specification itself. This should definitely be unified. If aria-level is really limited to 1-6 for headings, then this issue and the Chromium bug would be solved. — Reply to this email directly, view it on GitHub <#1757>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAKQAZQBRRLA2P42WB6GOHTVPFAZTANCNFSM5YY7KXFA> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[scottaohara]

additional notes for this issue:

• indicate what happens (handling author errors) for if aria-value is greater than 9, or a negative value... zero...
• mention of capping at 9 to the aria-level and role=heading definitions

[jnurthen]

The spec now has a note about this.
https://w3c.github.io/aria/#aria-level
Can this be closed?