Originally Posted by RobOnLI

It isn't any kind of "special logic" to zero out PZ when PZ is not zeroed out and IS working. People on this thread just can't find the right flights. For example ORD-MSP on 2-7 has PZ1 I1 IN1 on the 610pm departure. So PZ does exist. The fact that people aren't seeing PZ when booking but getting upgraded at a later time simply means PZ opened before the upgrade window and the upgrade processed. I'm simply suggesting this is a REAL possibility.

-RM