Ten-four
Meaning
An affirmative response signifying understanding, agreement, or confirmation of a message received.
Origin
In the crackling world of early 20th-century radio communication, clarity was paramount, especially for law enforcement. To cut through static and save precious airtime, the Association of Public-Safety Communications Officials (APCO) devised the "10-code" system in 1937. Each code was a concise shorthand for common phrases, and "10-4" was specifically designated for "Ok" or "Message received." While initially a police and emergency service standard, its true fame exploded in the 1970s. With the boom of CB radio, truck drivers embraced these codes, making "ten-four" a household phrase, a rugged, efficient way for anyone to signal perfect understanding on the open road and beyond.
Examples
- I'll meet you at the diner around noon, ten-four?
- The dispatcher confirmed the details, 'Ten-four, I've got the updated location.'