Originally Posted by
yul7075
LM Upgrade is processed in the DCS (Departure Control System) and never changes the booking Class on the PNR
the seat is taken from the highest J inventory
R is exclusively reserved for eupgrades
Don't think so. Anytime I've done an LMU I've seen the fare code change when I go an view the itinerary on AC.com. I'm not saying that LMU is taken from R space, just that the PNR is changed to say R when an LMU is purchased.