For the most part,
Priority baggage tags seem to be a more pervasive joke than the token "knock-knock" riddle. Sometimes they help--but in my experience, such tagged bags get the same treatment as a "naked" bag.
As far as the rules, like any institution at UA, it
depends who you talk to. I've had bags tagged (as either a 1P or 2P) with some segments in F or C; other times, if I wasn't traveling an entire journey in F or C, the CSR would find the Y segment and rationalize his/her refusal to attach priority tags.
The best baggage service I've found thus far...carry-on!
[This message has been edited by UNITED959 (edited 02-17-2003).]