Lest we forget:
The "Guest" classification was created because some trolls were posting over other Mudcatter's signatures. All it meant was that the name following the "guest" designation wasn't necessarily the name of a member. So I couldn't post as BillD or Clinton Hammond or Shambles, for example.
Posting simply as "Guest" is simply rude, in the order of sending a letter with no return name or address. the only problem with posting as "GUEST:Whatever" is that anyone can use that handle, and responses become muddled-to-impossible.