这个词应该来自于军事通讯，因为以前军队中的通讯员经常要把通讯的内容写下来或打（字）下来呈递指挥官，所以，“Do you copy that?" 的意思是问：Can you make a perfect copy of what I said?
在英语世界，无线电通讯中有一套通行的专门用语来确保能够清楚、简洁地传递信息，叫做 Voice procedure，其中比较常用的有：
Affirmative — Yes
Negative — No
Reading you Five / Loud and clear — I understand what you say 5x5.
Over — I have finished talking and I am listening for your reply. Short for "Over to you."
Out — I have finished talking to you and do not expect a reply.
Clear — I have finished talking to you and will be shutting my radio off.
Roger — Information received/understood.
Copy — I understand what you just said (after receiving information).
Wilco — Will comply (after receiving new directions).
Go ahead or Send your traffic — Send your transmission.
Say again — Please repeat your last message (Repeat is not used as it is a specific command when calling for artillery fire)
Break — Signals a pause during a long transmission to open the channel for other transmissions, especially for allowing any potential emergency traffic to get through.
Break-Break — Signals to all listeners on the frequency, the message to follow is priority.