Example of a booking facilitation done by an airline GDS:
A mirror image of the passenger name record in the airline reservations system is maintained in the GDS system. If a passenger books an itinerary containing air segments of multiple airlines through a travel agency, the passenger name record in the GDS system would hold information on his entire itinerary, each airline he flies on would only have a portion of the itinerary that is relevant to them. This would contain flight segments on their own services and inbound and onward connecting flights (known as info segments) of other airlines in the itinerary. e.g. if a passenger books a journey from Amsterdam to London on KLM, London to New York on British Airways, New York to Frankfurt on Lufthansa through a travel agent and if the travel agent is connected to Amadeus GDS. The PNR in the Amadeus GDS would contain the full itinerary, the PNR in KLM would show the Amsterdam to London segment along with British Airways flight as an onward info segment. Likewise the PNR in the Lufthansa system would show the New York to Frankfurt segment with the British Airways flight as an arrival information segment. The PNR in British Airways system would show all three segments. One as a live segment and the other two as arrival and onward info segments.