Originally Posted by R2

I assume you mean U class ticket? Your boarding pass is either Economy or Business (or First) and the booking class is in your ticket.

To answer AMRivlin's question, I was there on an AY+ award ticket two weeks ago (QR flights, business class, booking class U) and had a 10 hour layover. I went to the transfer desk to request STPC. The agent checked on the computer and politely said I was not eligible because my ticket was an award ticket.