The practice of changing availability of seats for each booking code on a flight. This process ensures optimized revenue per seat sold and entails using detailed historical booking, fare, and profit information, with powerful algorithms for implementation. Many airlines use what is called O&D revenue optimization, which creates yield management models across a carrier's entire network, rather than on specific flights only. ATPCO's RBD data provides the link between inventory and price, and is used in these systems.