Military call signs are
call signs
In broadcasting and radio communications, a call sign (also known as a call name or call letters—and historically as a call signal—or abbreviated as a call) is a Identifier, unique identifier for a transmitter station. A call sign can be fo ...
(or callsigns) or specialized form of
nickname
A nickname, in some circumstances also known as a sobriquet, or informally a "moniker", is an informal substitute for the proper name of a person, place, or thing, used to express affection, playfulness, contempt, or a particular character trait ...
assigned as unique identifiers to military communications. In wartime, monitoring an adversary's communications can be a valuable form of intelligence. Consistent call signs can aid in this monitoring, so in wartime, military units often employ
tactical call signs and sometimes change them at regular intervals. In peacetime, some military stations will use fixed call signs in the international series.
United States military

The
United States Army
The United States Army (USA) is the primary Land warfare, land service branch of the United States Department of Defense. It is designated as the Army of the United States in the United States Constitution.Article II, section 2, clause 1 of th ...
uses fixed station call signs which begin with ''W'', such as WAR, used by U.S. Army
Headquarters
Headquarters (often referred to as HQ) notes the location where most or all of the important functions of an organization are coordinated. The term is used in a wide variety of situations, including private sector corporations, non-profits, mil ...
. Tactical call signs are often assigned to a
company
A company, abbreviated as co., is a Legal personality, legal entity representing an association of legal people, whether Natural person, natural, Juridical person, juridical or a mixture of both, with a specific objective. Company members ...
sized unit or higher. For example, the collective "Checkmate" might be assigned to an entire company and thus "Checkmate Red 6" would be the first
platoon
A platoon is a Military organization, military unit typically composed of two to four squads, Section (military unit), sections, or patrols. Platoon organization varies depending on the country and the Military branch, branch, but a platoon can ...
leader (platoons are red for first, white for second, blue for third, black for headquarters, and often additional colors for other portions under the command), "Checkmate white 6" to the second platoon leader, etc. "Checkmate 6" is the Company
Commander
Commander (commonly abbreviated as Cmdr.) is a common naval officer rank as well as a job title in many army, armies. Commander is also used as a rank or title in other formal organizations, including several police forces. In several countri ...
and "Checkmate 6 Romeo" is the commander's radio-telephone operator (Romeo the
NATO phonetic of the letter R). Under some conventions, 6 is designated the commander or leader, 5 the second-in-command or executive officer, 7 the chief NCO. Also, companies often have the letter they are designated by ('A', 'B', 'C' or 'D') be the first letter of their call sign. This means a 'C' Company could potentially have 'Checkmate' as its call sign. One specific call sign used Army wide is
DUSTOFF, dating back to the first dedicated Air Ambulance unit in
Vietnam
Vietnam, officially the Socialist Republic of Vietnam (SRV), is a country at the eastern edge of mainland Southeast Asia, with an area of about and a population of over 100 million, making it the world's List of countries and depende ...
.
Fixed call signs for the
United States
The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...
stations begin with ''A'', such as AIR, used by USAF Headquarters.
The USAF also uses semi-fixed identifiers consisting of a name followed by a two or three digit number. The name is assigned to a unit on a semi-permanent basis; they change only when the U.S. Department of Defense goes to
DEFCON
The defense readiness condition (DEFCON) is an alert state used by the United States Armed Forces. For security reasons, the U.S. military does not announce a DEFCON level to the public.
The DEFCON system was developed by the Joint Chiefs of Sta ...
3. For example, JAMBO 51 would be assigned to a particular
B-52 aircrew of the 5th Bomb Wing, while NODAK 1 would be an
F-16
The General Dynamics F-16 Fighting Falcon is an American single-engine supersonic multirole fighter aircraft originally developed by General Dynamics for the United States Air Force (USAF). Designed as an air superiority day fighter, it e ...
fighter with the North Dakota Air National Guard. Individual military pilots or other flight officers usually adopt a personal
aviator call sign
An aviator call sign or aviator callsign is a call sign given to a military pilot, flight officer, and even some enlisted aviators. The call sign is a specialized form of nickname that is used as a substitute for the aviator's given name. It is ...
.
The most recognizable call sign of this type is ''
Air Force One
Air Force One is the official air traffic control-designated Aviation call signs, call sign for a United States Air Force aircraft carrying the president of the United States. The term is commonly used to denote U.S. Air Force aircraft modifie ...
'', used when any Air Force aircraft is transporting the
U.S. President
The president of the United States (POTUS) is the head of state and head of government of the United States. The president directs the Federal government of the United States#Executive branch, executive branch of the Federal government of t ...
. Similarly, when the President is flown in a
U.S. Marine Corps helicopter, the call sign is
Marine One
Marine One is the call sign of any United States Marine Corps aircraft carrying the president of the United States. As of 2024, it is most frequently applied to a presidential transport helicopter operated by Marine Helicopter Squadron One (HMX ...
. When then-president
George W. Bush
George Walker Bush (born July 6, 1946) is an American politician and businessman who was the 43rd president of the United States from 2001 to 2009. A member of the Bush family and the Republican Party (United States), Republican Party, he i ...
, a former
Air National Guard
The Air National Guard (ANG), also known as the Air Guard, is a Reserve components of the United States Armed Forces, federal military reserve force of the United States Air Force, as well as the air militia (United States), militia of each U.S. ...
fighter pilot, was flown to the
aircraft carrier
An aircraft carrier is a warship that serves as a seagoing airbase, equipped with a full-length flight deck and hangar facilities for supporting, arming, deploying and recovering carrier-based aircraft, shipborne aircraft. Typically it is the ...
USS ''Abraham Lincoln'' in a Navy
S-3B Viking, it was the first use of the "Navy One" call sign.
The
United States Navy
The United States Navy (USN) is the naval warfare, maritime military branch, service branch of the United States Department of Defense. It is the world's most powerful navy with the largest Displacement (ship), displacement, at 4.5 millio ...
,
United States Marine Corps
The United States Marine Corps (USMC), also referred to as the United States Marines or simply the Marines, is the maritime land force service branch of the United States Department of Defense. It is responsible for conducting expeditionar ...
, and
United States Coast Guard
The United States Coast Guard (USCG) is the maritime security, search and rescue, and Admiralty law, law enforcement military branch, service branch of the armed forces of the United States. It is one of the country's eight Uniformed services ...
use a mixture of tactical call signs and international call signs, with ships beginning with the letter ''N''. For example, the carrier
USS ''John F. Kennedy'' had the call sign NJFK for unclassified and navigation communications with other vessels, but uses tactical call signs that vary with its mission.
Navy and Marine Corps aircraft will typically use a stateside naming convention based on the aircraft tail code, identifying the squadron or air wing assigned, and a three digit number painted on the aircraft's nose known as the MODEX. Examples might be "November Lima Two-Zero-One" or "Navy November Lima Two-Zero-One." Another option would be to use a unit callsign from the publication known as JANAP 119, such as "Old Nick Two-Zero-One." A Marine Corps aircraft might use a call sign like "Marine Delta November One-Zero-Two" or "Shamrock One-Zero-Two." Other tactical call signs may be employed as mission necessities dictate.
Coast Guard aircraft callsigns are almost always the word "Coast Guard" and the 4-digit aircraft number, e.g., "Coast Guard Six-Five-Seven-Niner," although other call signs may be used for special operations such as counter-narcotics interdiction.
In tactical situations, the Marine Corps utilizes call signs naming conventions similar to the Army's.
In May 2019, United States Navy announced new procedures for assigning call signs to pilots in training to avoid potentially racist names.
United Kingdom military
Tactical voice communications ("combat net radio") use a system of call signs of the form ''letter-digit-digit''. Within a standard infantry battalion these characters represent companies, platoons and sections respectively, so that 3 Section, 1 Platoon of B Company might be F13. In addition, a suffix following the initial call sign can denote a specific individual or grouping within the designated call sign, so F13C would be the Charlie
fire team. Unused suffixes can be used for other call signs that do not fall into the standard call sign matrix, for example the unused 33A call sign is used to refer to the
Company Sergeant Major
The company sergeant major (CSM) is the senior non-commissioned soldier of a company in the armies of many Commonwealth countries, responsible for administration, standards and discipline. In combat, their prime responsibility is the supply of ...
.
The letter part of the call sign is not the company's letter (B vs F in the above example). Instead, letter designations are randomly assigned using
BATCO sheets, and appear on CEIs (communication electronic instructions), and change along with the BATCO codes every 24 hours. This, together with frequency changes and voice procedure aimed at making every unit sound the same, protects the military against simple
traffic analysis
Traffic analysis is the process of intercepting and examining messages in order to deduce information from patterns in communication. It can be performed even when the messages are encrypted. In general, the greater the number of messages observ ...
and eavesdropping. Other radio users, like
B20, do not fit into the standard battalion model but are also assigned a call sign for protection.
The controller of each net has the call sign 0 ("zero"). There may also be a second controller – either a backup station or a commander who has delegated communication tasks to a signaller but may occasionally wish to speak in person – using the call sign 0A ("zero alpha").
Pre-BATCO systems used a series of appointment titles to identify users and individuals, "
Sunray", for instance, referring to the appropriate leader. Most appointment titles are no longer used by the British Army, but titles such as "Sunray" and "Sunray Minor" are still used; appointment titles also continue to be taught during
Community Cadet Forces
The Community Cadet Forces is a term used by the United Kingdom Ministry of Defence (MOD) to group together the Sea Cadet Corps, Army Cadet Force, Air Training Corps, and Volunteer Cadet Corps. Together with the Combined Cadet Force (CCF) the ...
communications training. Several other
Commonwealth
A commonwealth is a traditional English term for a political community founded for the common good. The noun "commonwealth", meaning "public welfare, general good or advantage", dates from the 15th century. Originally a phrase (the common-wealth ...
militaries and cadet forces used or continue to use appointment titles, including those of Australia, Canada, New Zealand, Zimbabwe, and Sierra Leone, with some usage by the United States military and various NATO countries also occurring due to a list of appointment titles being included in
ACP 125;
Commonwealth and ACP 125 appointment titles have a high degree of commonality with those used in British service, though differences, additions, and subtractions can be found (the British themselves used an altered version of their appointment title list during
Operation Banner
Operation Banner was the operational name for the British Armed Forces' operation in Northern Ireland from 1969 to 2007, as part of the Troubles. It was the longest continuous deployment in British military history. The British Army was initia ...
where certain titles had different meanings than usual or were replaced by alternative titles). Where there is continued usage of appointment titles, they are usually regarded as only giving a low grade of security cover,
[ with ACP 125 deeming them to be unclassified.][
]
See also
*Aviator call sign
An aviator call sign or aviator callsign is a call sign given to a military pilot, flight officer, and even some enlisted aviators. The call sign is a specialized form of nickname that is used as a substitute for the aviator's given name. It is ...
*Brevity code
Brevity is concision or brevitas, the quality of being brief or concise, or:
* Brevity (comic strip), ''Brevity'' (comic strip), a comic strip created by Guy Endore-Kaiser and Rodd Perry
* Brevity code, a vocal word replacement system
* Operation ...
*List of ICAO aircraft type designators
A list is a set of discrete items of information collected and set forth in some format for utility, entertainment, or other purposes. A list may be memorialized in any number of ways, including existing only in the mind of the list-maker, but ...
*NATO phonetic alphabet
The International Radiotelephony Spelling Alphabet or simply the Radiotelephony Spelling Alphabet, commonly known as the NATO phonetic alphabet, is the most widely used set of clear-code words for communicating the letters of the Latin/Roman ...
* Spacecraft call signs
References
{{Call signs
Call signs
Military