I always thought that "I copy that" was derived from an Italian "capisci" (capire = understand), but today I've read that this may be a radio slang only, not being derived from any other phrase.
What is the truth?
English Language & Usage Stack Exchange is a question and answer site for linguists, etymologists, and serious English language enthusiasts. It only takes a minute to sign up.Sign up to join this community
Radio slang is correct.
This term was introduced by truckers operating on Citizen Band radios. Truckers often came up with their own terms and verbage to use on the radio, most often so that law enforcement couldn't understand their messages.
As a little side note, you will often hear the term "Wilco" in conjunction with "Roger"... "Roger Wilco".... For what its worth, "Wilco" is short for "Will Comply". When you say Roger Wilco, you are saying, I receved your message and I will comply.