With UA you can see pretty easy on the boarding pass if someone is elite level w/UA.

UA calls F, then 1k, premex, premier, members of MP to board.

so someone w/out the above should not board until row is called, but as stated rarely have I seen the gate agent tell the non-elite pax to step aside.

When enforced, I view it as a perk of being elite on UA

edited to add: I go and stand by the gate and wait until I'm called to board either by row or status

[This message has been edited by Sweet Willie (edited 09-26-2002).]