It was introduced into 2002 March, top-level domain (TLD)foraeronauticalindustry. The international organization which puts the base on Switzerland, international air intelligence communication mechanism (SITA: Societe Internationale de Telecommunications Aeronautiques) at one of the sponsorequipped top-leveldomain(sTLD) which is managed, it can register the airport and the airliner and aeronautical station etc..

It is not the case that can register everyone, it is restricted to only the related organization and enterprise of aeronautical industry. In aeronautical industry the cord/code of the alphabet 2 - 3 letters where IATA (International Air Transport Association) and ICAO (international private aviation device) and FAA (Federal Aviation Administration) etc. have issued in the identification of the airport and the airliner is used in order to be used with each device, but thiscord/code as a 2nd level domain name it is reserved, the third party cannot acquire.