Hoping this ends the lamentations of people forgetting to sign in before posting a comment, and using an already-registered name. Impostercide should now do something like this:
You are attempting to post a comment with information (i.e. email address or login ID) belonging to a registered user. If you have an account on this site, please login to make your comment. Otherwise, please try again with different information. Copy and paste the comment below into another document before returning to the previous page or you may lose the comment.
Don’t mind me, testing Impostercide updates.
Let me know if this mangles anything else. It shouldn’t; it was a very simple tweak.