Originally Posted by
rktj
Sorry to jump in but this is somewhat related - regarding fare class inventory. How to decipher plenty of availability in Polaris (all 9's and plenty availability for cash purchase) but PZ0 and PN0. This is for ORD-HND in about 6 weeks.
The way to decipher it is that UA no longer releases very much in the way of upgrade space (PN and especially PZ) in advance. Most upgrade inventories seem to be released only within a couple of days of the flight.