Originally Posted by
sfvoyage
For an involuntary change, isn't the policy exactly the same as for a voluntary change, since R is already the lowest RBD for J cabin. What is the difference?
AIUI, for involuntary changes, rebooking is into the lowest RBD available
at the time of rebooking. So, if R is not available, the next one up, free of charge. (It could even be full-fare C if nothing lower is available). Voluntary changes would have to pay the fare difference, in this case.