Here are some procedural words frequently used in radio communication, and frequently heard in movies and on TV.
OVER: I've finished my transmission, it's your turn. 这好像是最常听到的一个口令了。
OUT: I have finished my transmission. 对话完了就要说"OUT",千万别还OVER,OVER个没完。转换通信频道前也要说"OUT".
READ BACK: Please read back what you've reveived from me.
ROGER: I've received your last transmission. "roger" is the voice code for letter "R", which means "o.k.understood" in early days of communication. (我以前一直以为这roger是从"read you"来的。It sounds like that, doesn't it?)
WILCO: (I copy and) will comply.
LOUD AND CLEAR: the signal is strong and of good readability. 其实这是两个口令，loud 表示信号足够强，clear表示接收得很清楚。
AFFIRMATIVE: Yes
Negative: No
MESSAGE: I have a message for you.
SEND: I'm ready, please send your message.
MAYDAY: Help me! 最紧急的求救信号，来自法语 m'aidez.
SILENCE: All stations please cease transmission (made by network controller).
BREAK! BREAK! BREAK!: All stations cease transmission. 用于极紧急的情况下，也是由控制员发出。