10-4 is a common radio response used in the United States as a means of acknowledging an incoming transmission. It translates to "I received your message loud and clear" or "understood." The use of 10-4 has become so widespread among American police officers on police radio that it is sometimes referred to simply as "The Ten Four.", 10-4 is one such numerical code. It’s part of the ten code which military and emergency services use, and essentially the code just means that you’ve heard and understood what has been conveyed to you. Of course, when outside of these entities, 10-4 is just a way for other people to say they’ve heard you., Next time someone tells you “10-4,” consider using one of these five easy responses – “Copy that,” “Roger that,” “Acknowledged,” “Understood,” or “Affirmative” – to keep the conversation flowing smoothly., People across the United States know the very popular 10-4, but like many other common phrases, not many know where it comes from. In honor of it being October 4th, let's take a look at the origin of the universal trucker lingo., 10-4 means "OK" or "Understood". It is used to confirm that a message has been properly received and comprehended. 10-4 originates from the 10-codes – a set of brevity words used in radio communications across various industries like law enforcement, emergency services, transportation, and more., Meaning “10-4” is a part of the “ten code” terms used in law enforcement and the military, as well as in truck driver communications. When you say “10-4”, you’re using it as a confirmation that you received information from another party, and you are acting on that information..