I notice that two tags have appeared, vernacu and vernacula. Are these words that I don't understand or typos for vernacular? If the latter, what should I do about it?
Tags are automatically deleted within a short amount if time if they have no posts. So the proper way to deal with misspelled tags that cover a small number of questions is to re-tag. In this case, neither of the tags have posts associated with them, so these tags should disappear soon.
If the misspelling is particularly common and recurrent, it may be worth merging with the proper spelling.