What Does 10-4 Mean | Police, Military, and Radio Codes 2026

Last updated: January 15, 2026 at 4:45 pm by Admin

Communication codes like 10-4 have long been a staple in police, military, and radio talk culture, but many people don’t know their origins or full meaning. 

From police codes to CB talk, these numeric phrases have shaped how professionals and even civilians communicate quickly and clearly. 

This article dives deep into the history, context, and cultural significance of 10-4 and related Ten codes, providing a complete guide for anyone curious about this iconic phrase.

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What Is 10-4?

At its core, 10-4 is a shorthand police code that means “Acknowledged” or “Yes.” It’s part of the larger system of Ten codes, which are numeric phrases used to convey messages quickly over radio communication.

Originally designed to reduce confusion over the airwaves, 10-4 allows responders to confirm receipt of a message without lengthy explanations. It’s concise, universally understood in professional communication, and has even found its way into everyday language and texting.

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History of 10-4

10-4 and other Ten codes originated in the 1930s and 1940s. The Association of Public-Safety Communications Officials (APCO) created these codes to standardize police communication across different jurisdictions.

Before Ten codes, officers had to speak long messages over radios, which were often unclear or distorted. By assigning numeric codes to common phrases, APCO made communication faster, safer, and less prone to misinterpretation.

Over time, 10-4 spread beyond law enforcement. The military adopted it, truckers used it on CB radios, and it eventually made its way into popular culture, from movies to music.

Fun fact: During the 1970s, CB talk 10-4 became a national craze in the U.S., immortalized in songs like “Convoy.”

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10-4 in Police and Law Enforcement

For police officers, 10-4 in police communication is more than just a casual acknowledgment. It ensures clarity during high-stress situations where every second counts.

Officers often combine 10-4 with other police 10 codes to provide updates quickly:

• 10-5 – Relay message
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• 10-7 – Out of service / Dead
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• 10-20 – Location
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Table: Common Police 10 Codes

Code	Meaning	Context
10-4	Acknowledged / Yes	Police / Radio
10-5	Relay message	Police / CB
10-7	Out of service / Dead	Police / Military
10-8	In service / Available	Police
10-20	Location	Police / CB

Using these codes reduces miscommunication, ensures officer safety, and keeps radio traffic efficient.

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10-4 in Military Communication

Military 10-4 works much like it does in law enforcement: it’s a confirmation code. Soldiers and officers use it to acknowledge orders or instructions over radios.

However, military communication often adds more structured reporting than police communication, with strict protocol for when and how to respond. For example, “10-4” confirms receipt, but does not indicate completion of the task, which might require a follow-up report.

10-7 meaning dead is particularly relevant in the military, signifying a soldier or unit is off-duty, unavailable, or “dead” in radio terms.

Quote: “In the field, one wrong message can cost lives. Codes like 10-4 save both time and confusion.”

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10-4 in Trucking and CB Radio Culture

Long before texting and smartphones, truckers relied on CB talk 10-4 to communicate while on the road. Using radio talk 10-4, truckers could acknowledge messages about traffic, weather, or road hazards without stopping.

Common CB phrases:

• “10-4 good buddy” – A friendly acknowledgment
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• “Breaker 1-9” – Opening a channel
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• “10-20” – Asking for location
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Table: Common Trucking 10 Codes

Code	Meaning	Context
10-4	Acknowledged / Yes	Truckers / CB
10-5	Relay message	Truckers / CB
10-7	Out of service / Dead	Truckers / CB
10-20	Location	Truckers / CB
10-9	Repeat message	Truckers / CB

CB radio culture helped cement 10-4 in American pop culture, appearing in songs, TV shows, and movies. Even today, some long-haul truckers still use these codes, blending old-school communication with modern GPS and mobile tech.

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10-4 in Digital Communication and Texting

The rise of texting and digital messaging brought 10-4 in texting to everyday life. People now use it to say “Yes” or “Message received” in informal conversations.

Examples:

• Friend: “Meet at 7?”
  You: “10-4” ✅
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• Colleague: “Send the report by noon.”
  You: “10-4, on it.”
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It’s a direct nod to its radio communication roots, but with a digital twist. Younger generations may not know its origin, but they still use it as shorthand acknowledgment.

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Variants, Synonyms, and Alternate Forms

The phrase 10-4 has multiple written forms. All carry the same meaning, but some are more common in certain contexts:

• 10 4
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• 10- 4
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• 10 – 4
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• 10–4
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People also search for phrases like:

• “What does 10 4 mean”
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• “What does 10-4 mean”
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• “Does 10 4 mean yes”
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Related codes:

• 10-5 meaning code – Relay message
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• 10-7 meaning dead – Out of service
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These variations and related codes help users adapt the shorthand to police, military, trucking, CB, and texting contexts.

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Mathematical, Cultural, and Slang Uses

While uncommon, 10-4 in math appears in coding exercises, puzzles, or educational examples as a simple numeric pair.

Culturally, 10-4 has permeated media, music, and internet slang. For example:

• Movies often depict police radio talk with 10-4 confirmations.
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• Songs like “Convoy” and pop culture references cemented CB talk 10-4 in public awareness.
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• Memes and texting culture occasionally misuse or humorously exaggerate its meaning.
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In casual conversation, saying “10-4” signals agreement, acknowledgment, or understanding in a playful, sometimes nostalgic way.

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How 10-4 Fits Into the Bigger Picture of Communication Codes

Communication codes like 10-4 are essential for fast, clear exchanges in any profession where clarity matters.

Key benefits:

• Saves time by replacing full sentences with concise numeric codes.
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• Reduces errors over radio or digital channels.
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• Creates a sense of professional culture and identity.
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Infographic idea: “10-4 Across Industries” could illustrate its use in police communication, military slang, trucking, and CB radio culture, highlighting the universal adoption of this simple phrase.

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Common Misconceptions About 10-4

Several myths surround 10-4 meaning:

• Myth: 10-4 always means “Everything is okay.”
  
  • Reality: It strictly means “Acknowledged” or “Yes,” not “All clear.”
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• Myth: 10-4 and 10-7 are interchangeable.
  
  • Reality: 10-7 meaning dead indicates out-of-service status, not acknowledgment.
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• Misuse in texting and casual conversation sometimes confuses newcomers.
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Understanding the distinction ensures accurate communication across professional and casual contexts.

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Quick Reference Table of 10 Codes

Here’s a table summarizing the most common police, military, and CB 10 codes for easy reference:

Code	Meaning	Context
10-4	Acknowledged / Yes	Police / Military / Trucking / CB
10-5	Relay message	Police / CB / Trucking
10-7	Out of service / Dead	Police / Military / Trucking
10-8	In service / Available	Police / Military
10-9	Repeat message	Police / Trucking / CB
10-20	Location	Police / Trucking / CB
10-33	Emergency / Assist	Police / CB
10-97	Arrived at location	Police / Military

This table ensures that anyone reading can quickly understand and use these codes correctly.

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Why 10-4 Endures Today

Despite technological advances, 10-4 remains a timeless shorthand. Its adoption in police communication, military slang, trucking radio culture, and texting highlights its versatility.

Even in the digital age, the need for fast, concise acknowledgment persists, making 10-4 meaning relevant to anyone who communicates over radio, text, or casual conversation.

Whether on the road, in law enforcement, or chatting with friends, 10-4 continues to bridge generations, industries, and technologies.

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Conclusion

10-4 is more than a numeric code—it’s a symbol of clear, effective communication across police, military, trucking, and CB radio culture. From its origins in the 1930s with Ten codes to modern texting and pop culture references, it has stood the test of time. Understanding 10-4 meaning, its variants, and related codes like 10-5 and 10-7 ensures you’re always in sync, whether on radio talk, in digital communication, or exploring CB talk 10-4 history.