I meant less mileage then normally needed for booking award travel.
( reduced amount of mileage needed=mileage reduction )
re·duc·tion noun \ri-ˈdək-shən\
Definition of REDUCTION
1) the act or process of reducing
In this case it would be mileage being reduced. sorry for the vagueness
vague –adjective, va·guer, va·guest.
Definition: not clearly or explicitly stated or expressed