Joint Electronics Type Designation System

The Joint Electronics Type Designation System (JETDS), which was previously known as the Joint Army-Navy Nomenclature System (AN System) and the Joint Communications-Electronics Nomenclature System, is a method developed by the U.S. War Department during World War II for assigning an unclassified designator to electronic equipment. JETDS is described in detail by MIL-STD-196.

Computer software and commercial unmodified electronics for which the manufacturer maintains design control are not covered.

Usage
Electronic material, from a military point of view, generally includes those electronic devices employed in data processing, detection and tracking (underwater, sea, land-based, air and space), recognition and identification, communications, aids to navigation, weapons control and evaluation, flight control, and electronics countermeasures. Nomenclature is assigned to:
 * Electronic material of military design
 * Commercial electronic material that has been modified for military use and requires military identification and design control
 * Electronic material which is intended for use by other Federal agencies or other governments that participate in the nomenclature system.

Systems
In the JETDS system, complete equipment sets or systems are designated with a sequence of letters and digits prefixed by AN/, then three letters, a hyphen, a number, and (occasionally) some optional letters (AN/AAA-nnn suffixed by (Vn)- hardware/software version} or (T){training equipment} . The three letters tell where the equipment is used, what it does and its purpose. For example, the AN/PRC-77 is a Portable Radio used for two way Communications. The numbers for any given type of equipment are assigned sequentially, thus higher numbers indicate more modern systems.

The three letter codes have the following meanings:

First letter: installation

 * A - Piloted Aircraft
 * B - Underwater Mobile (submarine)
 * C - Cryptographic Equipment (NSA use only) (was Air Transportable)
 * D - Pilotless Carrier (drone, UAV)
 * F - Fixed Ground
 * G - General Ground Use
 * K - Amphibious
 * M - Ground Mobile
 * P - Human Portable
 * S - Water (surface ship)
 * T - Transportable (ground)
 * U - General Utility (multi use)
 * V - Vehicle (ground)
 * W - Water Surface and Underwater combined
 * Z - Piloted/Pilotless Airborne vehicles combined

Second letter: type of equipment

 * A - Invisible Light, Heat Radiation (e.g. infrared)
 * B - Comsec (NSA use only) (was Pigeon)
 * C - Carrier (electronic wave or signal)
 * D - Radiac (Radioactivity Detection, Identification, and Computation)
 * E - Laser (was NUPAC, Nuclear Protection & Control)
 * F - Fiber Optics (was Photographic)
 * G - Telegraph or Teletype
 * I - Interphone and Public Address
 * J - Electromechanical or inertial wire covered
 * K - Telemetering
 * L - Countermeasures
 * M - Meteorological
 * N - Sound in Air
 * P - Radar
 * Q - Sonar and Underwater Sound
 * R - Radio
 * S - Special or Combination
 * T - Telephone (Wire)
 * V - Visual, Visible Light
 * W - Armament (not otherwise covered)
 * X - Fax or Television
 * Y - Data Processing
 * Z - Communications (NSA use only)

Third letter: purpose

 * A - Auxiliary Assembly
 * B - Bombing
 * C - Communications (two way)
 * D - Direction Finding, Reconnaissance and Surveillance
 * E - Ejection and/or Release
 * G - Fire Control or Searchlight Directing
 * H - Recording and/or Reproducing
 * K - Computing
 * L - no longer used. Was Searchlight Control, now covered by "G".
 * M - Maintenance or Test
 * N - Navigation Aid
 * P - no longer used. Was Reproducing, now covered by "H"
 * Q - Special or Combination
 * R - Receiving or Passive Detecting
 * S - Detecting, Range and Bearing, Search
 * T - Transmitting
 * W - Automatic Flight or Remote Control
 * X - Identification or Recognition
 * Y - Surveillance (target detecting and tracking) and Control (fire control and/or air control)
 * Z - Secure (NSA use only)

Model number
Following the three-letter designation, after a dash, is a number, uniquely identifying the equipment. Different variants of the same equipment may be given an additional letter and other suffixes (for example, AN/SPY-1A, AN/SPY-1B, etc.), while entirely new equipment within the same category is given a new number (for example, AN/SPY-3).

Variants and training equipment
A suffix of the three characters "(V)" (capital V) followed by a serially generated numeric configuration identifier is appended to the three-letter designation above to specify a particular hardware configuration.

A suffix of "(T)" (capital T) indicates training systems.

For example:

AN/ABC-1(V)4 would be the 4th variant of the AN/ABC-1 equipment.

Subsystems
Subsystems ("groups") are designated by a two letter code (without the AN/ prefix), followed by a number, followed by slash and one, two or three letters from the three letter codes for systems. For example, BA-1234/PRC would be a battery for portable radio sets.

History
JETDS was adopted 16 February 1943 by the Joint Communications Board for all new Army and Navy airborne, radio, and radar equipment. Over time it was extended to cover the Marine Corps and the Navy's ship, submarine, amphibious, and ground electronic equipment. When the Air Force was established as a separate department, it continued the use of the system for electronic equipment. JETDS was adopted by the United States Coast Guard in 1950, Canada in 1951 and the NSA in 1959 (though the NSA continued to use its own TSEC telecommunications security nomenclature ). In 1957 the U.S. Department of Defense approved a military standard for the nomenclature, MIL-STD-196. The system has been modified over time, with some types (e.g. carrier pigeon -B-) dropped and others (e.g. computers and cryptographic equipment) added. The latest version, MIL-STD-196E, was issued in 1998.