Call signs in Australia  Call signs in Australia are allocated by the Australian Communications and Media Authority and are unique for each broadcast station. The use of callsigns on-air in both radio and television in Australia is optional, so many stations used other on-air identifications. Australian broadcast stations officially have the prefix VL- and originally all callsigns used that format, but since Australia has no nearby neighbours, this prefix is no longer used except in an international context. The International Telecommunication Union has assigned Australia the following call sign blocks for all radio communication, broadcasting or transmission:  While not directly related to call signs, the International Telecommunication Union (ITU) further has divided all countries assigned amateur radio prefixes into three regions; Australia is located in ITU Region 3. It is assigned ITU Zones 55, 58 and 59, with the Pacific Islands in Australian jurisdiction in Zone 60. Australia is assigned CQ Zones 29 & 30. All radio call signs begin with a single-digit number indicating the state or territory, followed by two or three letters. In most cases, two letters are used for AM stations and three for FM, but there are some exceptions, such as 5UV in Adelaide, which broadcasts on an FM frequency, and 3RPH in Melbourne, which broadcasts on an AM frequency. While some AM stations retained their old call signs when moving to FM, most add an extra letter to the call sign. For instance, when 7HO Hobart became an FM station, it adopted the callsign 7HHO. Certain ABC radio stations, particularly outside of metropolitan areas, may use five-letter call signs for FM stations: "xABCFM" for ABC Classic FM, "xABCRN" for Radio National, and "xABCRR" for ABC Local Radio – the "x" being the state number. Also, SBS FM radio stations use a five-letter call sign, "xSBSFM". (Sydney and Melbourne's AM stations use "2EA" and "3EA", meaning "Ethnic Australia".) There are a number of exceptions:  The following are lists of Australian radio station call signs. Australian radios usually had the positions of radio stations marked on their dials. Australia's postcodes, introduced in 1967, use the same digit as the radio callsigns, followed by an additional three digits (eg. NSW: 2XXX, Victoria: 3XXX, etc.). There is an urban myth that call signs were based on Australian military districts but this incorrect as the following list of military districts show: 1 = Queensland; 2 = New South Wales; 3 = Victoria; 4 = South Australia; 5 = Western Australia; 6 = Tasmania; 7 = Northern Territory; 8 = New Guinea, and Papua.