radio call sign; radio call letters
A unique identifier assigned to a radio station or operator, used in broadcasting, aviation, maritime, and amateur radio.
Aircraft are assigned a unique radio call sign.
Amateur radio operators communicate using their own radio call signs.
Common loanword for 'call sign', used in the same contexts as 無線呼出符号 but more colloquial and frequent in everyday speech.
Compound of 無線 (radio), 呼出 (calling), and 符号 (code/sign). The term is a direct technical description of its function.