noun
radio call sign; radio call letters
A unique identifier assigned to a radio station or operator, used in broadcasting, aviation, maritime, and amateur radio.
航空機には固有の無線呼出符号が割り当てられている。
Aircraft are assigned a unique radio call sign.
アマチュア無線家は自分の無線呼出符号を使って交信する。
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.