Two digit Airline Designator - The designator is used to identify an airline for all commercial purposes. the two character airline designator is assigned by IATA in accordance with the provisions of Resolution 762. The two character airline designator listed are for use in reservations, timetables, tickets, tariffs, air waybills, schedules publications and in airline interline telecommunications, as well as for the airline industry applications. IATA assigns three types of two character airline designators. Unique, numeric/alpha and controlled duplicate.