While it's clear in the context of that one question, in general it just seems really vague as to what that tag means. The tag wiki could of course help, but since it is empty it isn't helping here at all. It also doesn't seem to me that even if defined a bit better it would create a useful tag, as it doesn't really add a significant grouping to this site. On top of all of that, there also aren't any other question with this same tag.
So should strong be a tag at all? If so what should it be about?