Reciprocal agreement by two or more airlines to offer their passengers single-booking, single-ticketing, and if there is no stopover, single check-in flights to a destination only one of them serves, all with no loss of frequent-flier mileage. In this agreement, the airlines share in all legs of the flight, using the same two-letter code used by travel agents that identifies the carrier in the Global Distribution System (GDS).
« CODES
