Your first line says:
> In the case of Invisible Content Just for Screen Reader Users, a WebAIM article concludes this:
So I was asking you to post the link to the article you read for the benefit of other users here...
I'm asking that if <strong> was used, could it suggest <strong>even more</strong> to a screen reader user, or, at least, to some of them, that it has encountered special content, for its benefit alone.
Over time screen reader users speed up the read back rate, and some disable the inflections as I noted. So the next thing would have a screen reader sound a chime to set off that special content is hit. This would either need a HTML tag or attribute, and that could open a can of worms.
What's wrong with HTML tags for screen readers only?
Some of the W3C members try to incorporate universal design, and groups (like mobility, learning disabilities) may get upset of catering the web to them. If a tag was created for screen readers only, naive developers may be like "Oh I am lazy today, I will shove my skip links in that special screen-reader-only tag." People with mobility impairments and "power users" find skip links benefitical for navigating a page. Well under that mindset, the developer just [unintentionally] excluded two groups of people.
We already have tags for screen displaying only: <i>, <b>. Visual elements are somehow better or have more legitimacy over auditory elements?
These are announced to a screen reader users (and some to most other speech output programs) if they want them to be. They have the choice, the reverse is not true. Currently there is no sniffing capabilities to detect AT, and been discussed at length. Personally, I can use the keyboard to do 85-90% of my daily activities if chose to. Thus making me near impossible to sniff.
is correct use for strong, for several reasons. I see a <b> element there, a <mark> element perhaps.
To AT, like browsers/HTML <strong> and <b> act the same way. I am not on the HTML5 bandwagon yet, so I will have to ask my contacts with W3C about the thought behind mark. It seems like <strong><b><i><em><u> to me. If a combination of those tags didn't work, I would either make a CSS class that overrules the default behavior of one of those tags, if I cared about it getting inflected. If I didn't I would just wrap the phrase in a <span> and apply CSS.
This is a legitimate use of <strong> for me:[...]
This is where this thought fails though. This could be extrapulated to making <strong> equivalent to parenthesis (). The point about parenthesis is if you remove the words that they are surrounding, the sentence still reads correctly. In both examples, taking out the bolded words, the sentence isn't complete.