Call signs are regulated internationally by the ITU as well as nationally by the Comisión Nacional de Comunicaciones of the Argentine government.
The International Telecommunication Union has assigned Argentina the following call sign blocks for all radio communication, broadcasting or transmission:[1] While not directly related to call signs, the International Telecommunication Union (ITU) further has divided all countries assigned amateur radio prefixes into three regions; Argentina is located in ITU Region 2.
Internally Argentina divides its regions according to the first or first-two letter(s) of the suffix, as shown in this table:[2]
[3] Foreign amateurs can contact the Radio Club Argentino for permission to operate in the country.
[5] In 1924, Argentina was assigned the single letter prefix 'R' as an informal convention to avoid confusion during trans-Atlantic radio tests.