Thanks.
I guess we need a new sticky in this forum for fare classes.

Here is a typical list of buckets and inventory I found for a IAD-BRU flight:
F5, FN5, A5, ON4, O1, J9, JN9, C9, D9, Z9, ZN9, P9, PN9, R2, RN2, IN0, I0, Y9, YN9, B9, M9, E9, U9, H9, HN9, Q9, V9, W9, S0, T0, L0, K0, G0, N0, XN0, X0