Re: 1.3.1 info and relationships

Patrick, That's a slightly different situation. I was talking generally, in
principle (which I think the original post was too). I'm saying that, in
principle, if content is presented as plain text (or other plain, simple
content) then 1.3.1 says that presentation must be passed to assistive
tech, even if that presentation is just plain text, so it's usually a fail
if other things are added without reasonable cause.

The obvious fail case is tables used for layout purposes - universally
condemned because it causes unwanted and misleading screen reader
announcements for no reason (except developer convenience!) That
"misleading" is important.

On the other hand there are, as you say, many situations where there is
good reason to add other things, but I think that reason must be in the
presentation, to comply with 1.3.1. There ought to be some justifiable
cause, in the visual presentation, for taking such action. (And I
personally think adding headings into unheaded content is not usually a
good example, as it is departing quite seriously from what is on the page.)

Take most navigation menus. We see visually what they are immediately, but
to a blind person they would be just several random links. So we give them
structure and explanation by putting them in a list and a <nav>
element and give them a label. The justification for this is the difference
in how a sighted person will see it (and make deductions that it's a
navigation menu based on layout and position), and how a blind person will
perceive them.

So it seems to me it all comes down, in the end, to "cause" and
"justification" in the presentation. If a sighted person will understand
something from the visual presentation (layout, position, or possibly even
from the words themselves), there is likely to be cause under 1.3.1 to make
that clear to AT.