Radio lingo
10-codes
Signal-codes
Law enforcement terms
Comms hardware
100

This spoken word is used on the radio to mean "I have received and understood your message."

 What is "Roger" (or "Copy")

100

This universal 10-code frequently means "Signal clear" or "All clear."

What is 10-4?

100

This code commonly means "Emergency / Lights and Siren.

What is Code 3?

100

The formal written record of an arrest and charges booked at the station.

What is a booking report (or docket)?

100

This standard band operates around 800 MHz and is widely used for public safety trunked radio systems.

(What is UHF/800 MHz?)

200

Used to interrupt a transmission when an emergency or high-priority message needs to go through.

What is "Break, Break"?

200

In many standard public safety codes, this number denotes an "Officer in trouble" or "Urgent assistance needed."

 What is 10-33 (or 10-12 in some jurisdictions)

200

This code is standard police lingo for "Mental subject / Emotional disturbance."

What is a Code 405 (or 5150)?

200

A temporary detention of a person by police based on reasonable articulable suspicion.

What is a Terry stop (investigative detention)?

200

This device converts digital data into analog radio signals and back again for mobile data terminals.

(What is a modem?)

300

The phonetic alphabet word used to represent the letter "M" during radio spells.

 What is "Mike"?

300

This code is commonly used to report an "Accident with property damage" or a traffic crash.

What is 10-50?

300

This code means "All clear / No further assistance needed."

What is Code 4?

300

The landmark 1966 Supreme Court case that established mandatory warnings before custodial interrogation.

What is Miranda v. Arizona?

300

This hardware component boosts a weak radio signal before it reaches the receiver.

(What is a repeater/amplifier?)

400

This term means to repeat back key parts of a message to ensure accuracy.

 What is "Read back"

400

Instead of 10-codes, many modern agencies transitioned to speaking in clear, plain text known by this acronym.

What is NIMS / ICS plain language?

400

This radio designation means "Officer in trouble / Need immediate assistance."

What is Code 33 (or Officer Down / 10-33)?

400

The standard phonetic alphabet word used for the letter "E" over police radios.

What is Echo?

400

This term describes the physical handheld radio carried by an officer on patrol.

(What is a portable transceiver/walkie-talkie?)

500

A standard radio check phrase asking how well your signal is coming through on a scale of one to five.

What is "Radio check" (or "How do you read me")?

500

This term refers to the unique identification number or radio call sign assigned to a specific patrol unit or beat.

What is a unit designator or call sign?

500

This three-letter standard governs cellular data networks succeeding 4G.

What is 5G?

500

A system that automatically sends a caller's exact geographic coordinates and phone number to a dispatch center.

What is Enhanced 911 (E911)?

500

This protocol standard allows digital land mobile radios from different makers to talk to each other.

(What is P25 - Project 25?)

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