Brevity Codes

From Freq Of Nature

Contents 1 Origin of Ten Codes 1.1 Project 4 1.2 Project 14 2 APCO Official Ten Signals

Origin of Ten Codes

10 Codes, or as they were initially called Ten Signals, were first introduced to public safety by the Association of Public-Safety Communication Officials (APCO) to set down a set of brevity codes for the purpose of standardizing their use on public-safety radio. Since then they have developed into many variations and have ironically become non-standard.

APCO's Project 4 was the development of the first Ten Signals which were published and sold to public-safety agencies. During the mid 1970's the list of codes was revised with APCO's Project 14.

Today the Ten Signals have been modified for each agencies use so much that even some of the original Ten Signals have lost their "official" meaning.

Project 4

In keeping with the trend toward standardization, APCO developed "Ten Signal Cards." The project was also a huge success for APCO, with tens of thousands of copies sold. Agencies, including the Division of Park Operations of the National Park Service, were quick to adopt the "ten signals" for official use. Although the actual signals and ten-codes have evolved over time, this project was the first attempt to address the need for standards in radio-use language, a basic tenet of interoperability.

Project 14

Project 14 studied the efficacy of the use and standardization of aural brevity codes, such as "10-4." Through surveys, the committee determined six benefits of using such codes, including improved accuracy within and between systems, a reduction in system response times, enhanced system discipline, increased privacy, more efficient use of training time and the applicability of such codes to the then-newly developing system keyboard indexing. They also discovered of the three possible code formats (alpha-only, alpha numeric and numeric-only), the numeric-only format was most suitable; they also found a need for a prefix and suggested the already popular "10" was the best choice and should be retained. The committee found a need for a standard code list to maximize interdepartmental cooperation and to minimize training concerns, because employees would not have to learn a new code list if they changed agencies. In addition to the code list, they determined a phonetic alphabet was also needed, to minimize confusion on the radio, and concluded the international phonetic alphabet already widely in use fulfilled the need adequately.

The result of Project 14 was the publication of a revised "Ten-Signal" aural brevity code, with the recommendation this list be adopted as a national standard. The committee members recommended the code be incorporated as standard keyboard characterizations in existing and future hardware specifications and used in information exchanges between fixed terminals of land mobile systems and on the criminal justice information network. They endorsed the international phonetic alphabet as the standard for the public service community. Finally, they recommended further study of the benefits of the future development of standard codes by individual radio service categories (fire, law enforcement, EMS) for use in conjunction with the listed aural brevity codes.

APCO Official Ten Signals

Ten Signal	Description
10-1	Signal Weak
10-2	Signal Good
10-3	Stop Transmitting
10-4	Affirmative (OK)
10-5	Relay (to)
10-6	Busy
10-7	Out of Service
10-8	In Service
10-9	Say Again
10-10	Negative
10-11	____ On Duty
10-12	Stand By (Stop)
10-13	Existing Conditions
10-14	Message/Information
10-15	Message Delivered
10-16	Reply to Message
10-17	Enroute
10-18	Urgent
10-19	(In) Contact
10-20	Location
10-21	Call ____ by Telephone
10-22	Disregard
10-23	Arrived at scene
10-24	Assignment Completed
10-25	Report to (Meet)
10-26	Estimated Arrival Time
10-27	License/Permit Information
10-28	Ownership Information
10-29	Record Check
10-30	Danger/Caution
10-31	Pick Up
10-32	____ Units Needed (Specify/Number/Type)
10-33	Help Me Quick
10-34	Time