10-4
Well, I work in "IT", but say 10-4 so often most of the people in the building say it too, and they don't even know what a CB is. Semi-funny related story:
Last Fall, this guy requests a couple data lines in the new lab they were setting up, along with a voice line and 'natch, I replied 10-4. A couple days later, he's at my office door vexing rage at the fact his lines aren't there. I told him "It takes more than a couple days to get this done", and he said "Why did you say it would be done on the 4th?"
Sure enough, he sent the request on October 3rd, and I replied the same day .....10-4...oh the pain..