10 codes

Tactical communications, like you hear on public safety radio, are all about being brief and to the point. In order to communicate quickly, codes and signals have been developed to allow personnel to get their point across using the minimum of words. There are numerous variations of 10 codes (abbreviations used by public safety officials to describe various conditions) used throughout the country. They can and do vary even from one county to the next.

Here is a Link to the Expanded APCO 10 Codes more commonly used today.

Generically, these are referred to as brevity codes; the linked article serves as an index to lists of such codes.

How 10 Codes have evolved

This table shows how 10 codes have evolved between 2 periods, years apart...

Code	1940 APCO definition	1974 APCO definition
10-1	Receiving poorly.	Signal Weak
10-2	Receiving well.	Signal Good
10-3	Stop transmitting.	Stop Transmitting
10-4	Acknowledgement.	Affirmative (OK)
10-5	Relay.	Relay (to)
10-6	Busy.	Busy
10-7	Out of service.	Out of Service
10-8	In service.	In Service
10-9	Repeat, conditions bad.	Say Again
10-10	Out of service - subject to call.	Negative
10-11	Dispatching too rapidly.	____ On Duty
10-12	Officials or visitors present.	Stand By (Stop)
10-13	Advise weather and road conditions.	Existing Conditions
10-14	Convoy or escort.	Message/Information
10-15	We have prisoner in custody.	Message Delivered
10-16	Pick up prisoner at ......	Reply to Message
10-17	Pick up papers at ......	Enroute
10-18	Complete present assignment as quickly as possible.	Urgent
10-19	Return to your station.	(In) Contact
10-20	What is your location?	Location
10-21	Call this station by telephone.	Call ____ by Telephone
10-22	Take no further action last information.	Disregard
10-23	Stand by until no interference caused to Iowa (Mo.) (etc.)	Arrived at scene
10-24	Trouble at station -- unwelcome visitors -- all units vicinity report at once.	Assignment Completed
10-25	Do you have contact with ...... ?	Report to (Meet)
10-26	Can you obtain automobile registration information from ...... ?	Estimated Arrival Time
10-27	Any answer our number ...... ?	License/Permit Information
10-28	Check full registration information (lic., motor, name, stolen, etc.)	Ownership Information
10-29	Check for wanted.	Record Check
10-30	Does not conform to rules and regulations.	Danger/Caution
10-31	Is lie detector available?	Pick Up
10-32	Is drunkometer available?	____ Units Needed (Specify/Number/Type)
10-33	Emergency traffic this station - clear?	Help Me Quick
10-34	Clear for local dispatch?	Time
10-35	Confidential information.	Reserved
10-36	Correct time?	Reserved
10-37	Operator on duty?	Reserved
10-38	Station report -- satisfactory.	Reserved
10-39	Your Nr ...... delivered to addressee.	Reserved
10-40	Advise is Officer ...... available for radio call.	N/A
10-41	Tune to ...... kcs. for test with mobile unit of emergency service.	N/A
10-60	What is next item (message) number?	N/A
10-61	Stand by for CW traffic on ...... kcs.	N/A
10-62	Unable to copy phone -- use CW.	N/A
10-63	Net directed.	N/A
10-64	Net free.	N/A
10-65	Clear for item (message) assignment?	N/A
10-66	Clear for cancellation?	N/A
10-67	Stattions ...... carry this item (message).	N/A
10-68	Repeat dispatch.	N/A
10-69	Have you dispatched ...... ?	N/A
10-70	Net message (State net traffic).	N/A
10-71	Proceed with traffic in sequence (busy here).	N/A

Links

http://www.apcohistory.org/pdf/1940-01-jan_pages1-12.pdf

http://freqofnature.com/index.php?m=Articles&p=Brevity%20Codes