ARIA and Accessibility API in HTML specification

[dSalieri]

What is the issue with the HTML Standard?

My question is a question of integrating algorithms from 3.2.9 Requirements related to ARIA and to platform accessibility APIs in HTML Accessibility API Mappings 1.0

If you take the first algorithm:

User agent requirements for implementing Accessibility API semantics on HTML elements are defined in HTML Accessibility API Mappings. In addition to the rules there, for a custom element element, the default ARIA role semantics are determined as follows: [HTMLAAM]

1. Let map be element's internal content attribute map.

2. If map["role"] exists, then return it.

3. Return no role.

Then it refers to the specification html Accessibleity API Mappings 1.0, but there is nothing similar to say or indicate the use of third-party algorithms when calculating the role. How does this algorithm fit into the specified integration of the specification html Accessibleity API Mappings 1.0?

Yes, in the specification, you can find a table for 3.5.12 autonomous custom element

HTML Specification	autonomous custom element
wai-aria-1.2	If the author assigned a conforming ARIA role using the role attribute, map to that role. Otherwise, the generic role.
Computed Role	Use WAI-ARIA mapping
MSAA + IAccessible2	Use WAI-ARIA mapping
UIA	Use WAI-ARIA mapping
ATK	Use WAI-ARIA mapping
AX	Use WAI-ARIA mapping
Comments

The table does not even hint that if an element is a custom element that has an ElementInternals object with the role IDL attribute set, then it should be taken into account if the role attribute with any value is not explicitly set on the custom element.

Apart from such the table for a custom element, I did not notice anything else. And then how does the algorithm integrate from the very beginning, could you clarify?