I've noticed a particular user* suggesting edits (of approximately the same content every time, asking users to refrain from tagging with it and explaining the purpose) to the untagged wiki and usage guidance every so often. These are usually accepted, but of course, the tag is then automatically deleted (within days at most) once all questions are retagged.
These repeated suggestions seem to me to be at best quite useless, and at worst borderline abusive, bumming a little free rep (which is not removed when the tag is, unlike suggestions on posts) for no actual benefit to the site. They're useless because untagged is just a feature of the software, and cannot be added to questions manually anyway.
*It doesn't really matter who, although I'm sure with a bit of digging one could figure it out.