photographer2012

Does airlines (and LH) usa FIFO (first in first out) or LIFO (last in first out) in their miles programs?

for example:
i flew 2 flights and the validation of the miles are 2 years

1. earned 1000 miles on 1/1/10
2.earned 2000 miles on 1/1/11

when i book an award ticket that costs 500 miles on 31/12/11 (for the example...don't get excited..)

would the miles go out of the miles i earned on the last or first flight?


Thanks!