Originally Posted by
Kvarko
Very interesting, thank you!
If you have time, can you tell me anything more about this? Where are the possible codes for each position specified? How do GDS and NDC differ in practical terms? How do the booking class and RBD differ?
AFKL haven't publicized the codes.
NDC is a more advanced booking system that has more support for bundling ancillaries into the fares; different airlines use it differently (AA, most notably, pulled all their cheap fares from the GDS).
Booking class/RBD is how so-called "dual inventory fares" are implemented. I'm more familiar with how DL does it (partly thanks to a poster on FT, xliioper), but the basic idea is that PE/Business/First(?) fare availability is governed by both the relevant booking class and an underlying economy class. So for DL (since I have no clue what AFKL's economy fare classes are), a Z fare could have an underlying X fare: they will have the same advanced purchase requirement, roundtrip requirement, etc., differing only in booking class and price. The fare is only valid if there is simultaneously Z and X availability.