ACTION-2107: Precedence of aria-details over aria-describedby

WRT completing ACTION-2107, Make editorial changes to aria-details, I have
one question.

 

What is the intended meaning of the following sentence from the aria-details
specification?

"When both aria-describedby and aria-details are provided on an element
aria-details takes precedence."

 

Since aria-details is not part of the name and description calculation, it
clearly does not refer to precedence in that calculation. Does it refer to a
user agent behavior? If not, whose is responsible for creating the
precedence, and how is that precedence manifest?

 

Thanks,

matt