if i understood correctly, the M fare upgrade availability for 1k/GS is tracked under PN and this is ONLY for (mostly) domestic or short-haul int'l flights. but when i look at long haul, european and south american flights, i still see PN>0, what's this for? i was going to purchase an M fare IAD-AMS on a flight with PN4 but RN0. not sure what that's worth except a higher priority for SWU clearance when (if) they become available. in this case, how do you get any of those PN seats? any thoughts?