I notice some question askers have been using the version number as a tag (e.g. 4.6.2) -- is that recommended, or is it better to just list it in the question itself?
Generally, we tag items to take advantage of search and favorites functionality. You set favorite tags, and questions with any of those tags will appear highlighted as you browse the site. You can also set up RSS or email feeds to get notified of new questions matching your favorite tags. I don't think a version number is super-useful when I am searching for things to answer; if I'm searching or asking a question, I would narrow down my search using tags that reference functional areas, before I would search by version.
I agree with Nicholai it doesn't seem like a great use of tags. A question tagged 4.4 might well be (probably is) still relevant to versions 4.6 and later.