What Does 10-4 Mean? The Origin & How To Use It - Car CB Radios

Where did 10-4 originate from?

Any of these are possible origins for 10-4, but there is one thing that's known for certain: It was first documented in the early 20th century. In 1939, Charles Cadell put out a list of "Radio Telephony Hand Signals with Codes" and included this term as an example of how to respond to an incoming transmission.

-You be interested in reading: What are the CB Radio codes

Interestingly enough, none of the sign language that he listed had any real meaning behind them; they were simply common ways to acknowledge or dismiss another conversation. This makes sense since Cadell released his hand signals at a time when most people didn't know what ASL (American Sign Language) was.

If you're ever unsure of what to say on the radio, "10-4" is one good and appropriate option. But if you really want to sound like a professional, try using "affirmative." Just remember though, if someone responds to your transmission with "10-4," it doesn't mean that they agree with you or that they'll do exactly what you say right away. It simply means that they received your message loud and clear.

And don't forget that 10-10 is also common in some states as a response meaning everything is okay (no problems). 

You may be interested in reading: What are the 10 Codes for CB Radios. 

How to respond to 10-4?

You've now learned that 10-4 means something along the lines of "I received your message loud and clear" or "understood." But how do you respond to this?

Responding with "10-4" is actually a pretty good idea, as others will know that you understand (as they would if you responded with "affirmative").

However, it's still polite to give an indication of what you plan to do after acknowledging their transmission. This can be done by adding on a statement such as ". . . I'll respond back shortly" or ". . . over." This just gives the other person more information – especially if he doesn't hear from you immediately.

Also remember that when responding to 10-4s, it's always a good idea to respond the same way the other person did.

If you hear someone respond "10-4," acknowledge their response with a "10-4" of your own.

If you're ever unsure about how to respond to something, simply look at what others are using and do the same or use something along those lines.

People are often hesitant to make transmissions over the radio for fear that they'll get it wrong, but remember that if there are many people going back and forth on the airwaves with no problem at all, you can probably manage just fine!

How long does 10-4 stay relevant?

It's been around since before we could even call out on radios made by Motorola. In fact, it's been around since the earliest days of radio when there were no set formats or any real way to confirm that you heard someone else's transmission.

In most cases, 10-4 and phrases like it have stuck around because they're useful and simple enough for individuals to understand. They can also be used in a variety of ways, allowing them to stay relevant over time.

10-4 is usually only really relevant when talking on radios. However, it can sometimes come up in other situations as well.

10-4 may also come upon other types of radio systems, such as CB radio (Citizen Band) or FRS (Family Radio Service). It's simply used to acknowledge that you received another person's transmission.

FRS radios are typically found on walkie-talkies and are commonly used by children or teenagers who want to have a little bit of fun with their friends without needing anything more complicated than a cheap handheld radio.

CB radio is usually reserved for people who use radios either for work purposes (such as truck drivers) or those who just enjoy talking with others over the airwaves.

-You may be interested: The 4 Types of CB Radios Explained. 

Why use the 10-4 code on the Radio?

10-4 is a common radio response used in the United States as a means of acknowledging an incoming transmission or message received. It translates to "I received your message loud and clear" or "understood."

Where did 10-4 originate from?

Any of these are possible origins for 10-4, but there is one thing that's known for certain: It was first documented in the early 20th century. In 1939, Charles Cadell put out a list of "Radio Telephony Hand Signals with Codes" and included this term as an example of how to respond to an incoming transmission.

Interestingly enough, none of the sign language that he listed had any real meaning behind them; they were simply common ways to acknowledge or dismiss another conversation. This makes sense since Cadell released his hand signals at a time when most people didn't know what ASL (American Sign Language) was.

If you're ever unsure of what to say on the radio, "10-4" is one good and appropriate option. But if you really want to sound like a professional, try using "affirmative."

Just remember though, if someone responds to your transmission with "10-4," it doesn't mean that they agree with you or that they'll do exactly what you say right away. It simply means that they received your message loud and clear.

And don't forget that 10-10 is also common in some states as a response meaning everything is okay (no problems).

10-4 is part of the ten codes, to learn more about these codes. 

What are ten codes?

Ten codes are code words used by law enforcement officers to communicate with one another in radio transmissions. They provide a standardized way of communication between officers and can help reduce the amount of time a police officer has to spend relaying detailed messages over the radio. Ten codes were created in 1937 as part of the National Association of Police Communications Officers (NAPCO) Code System, and they remain widely used throughout North America today. 

Common ten-codes include 10-4 (Message Received), 10-6 (Busy), and 10-20 (Location). Although most departments use some form of ten-code system, there is no universal standard for these codes; each department may use different codes for the same phrase. It’s important that officers are aware of the ten codes used in their jurisdiction and any regional variations.

Similarly, if a police officer is visiting an unfamiliar jurisdiction, they should familiarize themselves with the local codes before responding to calls.

Ten codes can help make radio transmissions more efficient while also providing officers with added security since it’s not obvious to outsiders what a transmission is referring to. By using ten codes, law enforcement officers can quickly convey important information in a concise manner.

How to respond to 10-4?

You've now learned that 10-4 means something along the lines of "I received your message loud and clear" or "understood."

But how do you respond to this?

Responding with "10-4" is actually a pretty good idea, as others will know that you understand (as they would if you responded with "affirmative"). However, it's still polite to give an indication of what you plan to do after acknowledging their transmission.

This can be done by adding on a statement such as ". . . I'll respond back shortly" or ". . . over." This just gives the other person more information – especially if he doesn't hear from you immediately. Also remember that when responding to 10-4s, it's always a good idea to respond the same way the other person did.

If you hear someone respond "10-4," acknowledge their response with a "10-4" of your own.

If you're ever unsure about how to respond to something, simply look at what others are using and do the same or use something along those lines.

People are often hesitant to make transmissions over radio for fear that they'll get it wrong, but remember that if there are many people going back and forth on the airwaves with no problem at all, you can probably manage just fine!

How long does 10-4 stay relevant?

It's been around since before we could even call out on radios made by Motorola. In fact, it's been around since the earliest days of radio when there were no set formats or any real way to confirm that you heard someone else's transmission.

In most cases, 10-4 and phrases like it have stuck around because they're useful and simple enough for individuals to understand. They can also be used in a variety of ways, allowing them to stay relevant over time.

10-4 is usually only really relevant when talking on radios. However, it can sometimes come up in other situations as well. For example, you might hear "10-4" being said between police officers who are not using their radios (or who aren't even anywhere near their cars).

This can occur very frequently when two officers pass by each other on the street while on patrol or in the middle of a foot pursuit.

Why use the 10-4 code on the Radio?