(i18n) 'auto' value for the 'dir' attribute? #1491
Description
The i18n self test says:
Values for the default base direction should include left-to-right, right-to-left, and auto. more
We do not have this for dir, there is a default for page-progression-direction. We could be inspired by the HTML specification. Note that the behavior of dir can also be modeled (or referred to?) the HTML spec.