What is the origin of the term "10-4?"

Answer by  patti (29325)

"Ten codes" were developed in the 1940s to minimize the talk on police scanners. The 10 is followed by another number, which is code. 10-4: "i heard you and acknowledge. "

Answer by  tiemze (8)

"10-4" is a term used by people who are communicating through CB radio. It is used to tell the listener that they understood what was being said. An example of this could include a trucker alerting another trucker that they're lights are off. The second trucker would respond "10-4".