Thanks for your replies and sorry for the question with the obvious
answer. I had actually already tried "tag UID FETCH 456 UID" and got
back "* 1 FETCH (UID 456)". Somehow I was experiencing a mental block
that wouldn't let me think of anything before the "FETCH" in the
response as actual useful parseable content, so I didn't even notice
the '1' was the msg sequence number, I only noticed that the server was
giving me the UID I just supplied it with. Anyway, thanks for clearing
that up.

- Macie