Originally Posted by
TerryK
I suspect OP is not familiar with fare rules and may have been confused. UA agent may have said that SFO-HKG segment can be used at a later date with only change fee, or no change fee, while changing destination requires refare.
AFAIK, this is not correct, and even if the residual value is used for an SFO-HKG segment later on, it will be refared.