Military rank

Military ranks are a system of hierarchical relationships in armed forces, police, intelligence agencies or other institutions organized along military lines. Usually, uniforms denote the bearer's rank by particular insignia affixed to the uniforms. Ranking systems have been known for most of military history to be advantageous for military operations, in particular with regards to logistics, command, and coordination; as time continued and military operations became larger and more complex, military ranks increased and ranking systems themselves became more complex.

Within modern armed forces, the use of ranks is almost universal. Communist states have sometimes abolished rank (e.g., the Soviet Red Army 1918–1935, the Chinese People's Liberation Army 1965–1988, and the Albanian Army 1966–1991 ), only to re-establish them after encountering operational difficulties of command and control.

Modern ranks
Modern military services recognize three broad categories of personnel. These are codified in the Geneva Conventions, which distinguish officers, non-commissioned officers, and enlisted men.

Apart from conscripted personnel one can distinguish:

Commissioned officers
Officers are distinguished from other military members (or an officer in training) by holding a commission; they are trained or training as leaders and hold command positions.

Officers are further generally separated into four levels:
 * General, flag, or air officers
 * Field or senior officers
 * Company grade or junior officers
 * Subordinate officer (naval cadet or officer cadet in the Canadian Forces)

General, flag, and air officers
Officers who typically command units or formations that are expected to operate independently for extended periods of time (i.e., brigades and larger, or flotillas or squadrons of ships), are referred to variously as general officers (in armies, marines, and some air forces), flag officers (in navies and coast guards), or air officers (in some Commonwealth air forces).

General-officer ranks typically include (from the most senior) general, lieutenant general, major general, and brigadier general, although there are many variations like division general or (air-, ground-) force general.

Flag-officer ranks, named after the traditional practice of showing the presence of such an officer with a flag on a ship and often land, typically include (from the most senior) admiral, vice admiral and rear admiral. In some navies, such as Canada's, the rank of commodore is a flag rank.

In the United Kingdom and most other Commonwealth air forces, air-officer ranks usually include air chief marshal, air marshal, air vice-marshal and air commodore. For some air forces, however, such as those of Canada, United States and many other air forces, general officer rank titles are used. Brazil and Argentina use a system of general officer ranks based on the term brigadier.

In some forces there may be one or more superior ranks to the common examples, above, that are given distinguishing titles, such as field marshal or general of the armies (many armies), fleet admiral (U.S. Navy), marshal of the Royal Air Force, or other national air force. These ranks have often been discontinued, such as in Germany and Canada, or limited to wartime and/or honorific promotion, such as in the United Kingdom and the United States.

In various countries, particularly the United States, these may be referred to as "star ranks" for the number of stars worn on some rank insignia: typically one-star for Brigadier General or equivalent with the addition of a star for each subsequent rank. In the United States, five stars has been the maximum used in all services (excluding the Marines and Coast Guard, which have only used four). There is also a theoretical six-star rank held by John J. Pershing and to which George Washington was posthumously promoted, referred to as the General of the Armies of the United States. Additionally, see admiral of the Navy for the US Navy's Six-Star equivalent, awarded to Admiral George Dewey and subsequently removed after his death.

Some titles are not genuine ranks, but either functions assumed by generals or honorific titles. For instance, in the French Army général de corps d'armée is a function assumed by some généraux de division, and maréchal de France, which is a distinction denoting the most superior military office, but one that has often neutered the practical command powers of those on whom it is conferred. In the United States Navy, a commodore currently is a senior captain commanding a squadron that is too small for a rear admiral to command, although that name has historically been used as a rank. The title (not rank) of commodore can also indicate an officer who is senior to a ship's captain (since only the ship's commander is addressed as captain while underway). Marine captains are referred to as major to distinguish themselves while shipboard.

Field or senior officers
Field officers, also called "field-grade officers" or "senior officers", are officers who typically command units that can be expected to operate independently for short periods of time (i.e., infantry battalions, cavalry or artillery regiments, warships, air squadrons). Field officers also commonly fill staff positions of superior commands.

The term "field(-grade) officer" is primarily used by armies and marines; air forces, navies and coast guards generally prefer the term "senior officer." The two terms are not necessarily synonymous.

Typical army and marine field officer ranks include colonel, lieutenant colonel, major and, in the British army, captains holding an adjutant's appointment. In many Commonwealth countries the field rank of brigadier is used, although it fills the position held by brigadier general in other countries.

Naval and coast guard senior officer ranks include captain and commander. In some countries, the more senior rank of commodore is also included. In others lieutenant-commanders, as equivalents to army and marine majors, are considered senior officers or Jerrie cadets.

Commonwealth air force senior officer ranks include group captain, wing commander, and squadron leader, where such ranks are still used.

Company grade or junior officers
The ranks of junior officers are the three or four lowest ranks of officers. Units under their command are generally not expected to operate independently for any significant length of time. Company grade officers also fill staff roles in some units. In some militaries, however, a captain may act as the permanent commanding officer of an independent company-sized army unit, for example a signal or field engineer squadron, or a field artillery battery.

Typical army company officer ranks include captain and various grades of lieutenant. Typical naval and coast guard junior officer ranks include grades of lieutenant commander, lieutenant, lieutenant junior grade, sub-lieutenant and ensign. Commonwealth (excluding Canada) air force junior officer ranks usually include flight lieutenant, flying officer, and pilot officer.

"The [U.S.] commissioned officer corps is divided into 10 pay grades (O-1 through O-10). Officers in pay grades O-1 through O-3 are considered company grade officers. In the Army, Marine Corps, and Air Force, these pay grades correspond to the ranks of second lieutenant (O-1), first lieutenant (O-2), and captain (O-3), and in the Navy, ensign, lieutenant junior grade, and lieutenant. Officers in the next three pay grades (O-4 through O-6) are considered field grade officers. In the Army, Marine Corps, and Air Force, these pay grades correspond to the ranks of major (O-4), lieutenant colonel (O-5), and colonel (O-6), and in the Navy, lieutenant commander, commander, and captain. The highest four pay grades are reserved for general officers in the Army, Marine Corps, and Air Force, and flag officers in the Navy. The ranks associated with each pay grade are as follows: in the Army, Marine Corps, and Air Force, brigadier general (O-7), major general (O-8), lieutenant general (O-9), and general (O-10); in the Navy, rear admiral-lower half, rear admiral-upper half, vice admiral, and admiral."

Subordinate/student officer
Officers in training in the Canadian Armed Forces are either naval cadet for Naval Training or officer cadet for Army or Air Force Training.

In the US and several other western forces, officers in training are referred to as student officers, and carry the rank of cadet (Army and Air Force) or midshipman (Navy, and in some countries, Marines). These officers may be serving at a military academy, or, as common in the United States, as members of a military training unit attached to a civilian college or university, such as an ROTC unit. This is due to a requirement that commissioned officers have at least a four-year degree. The British Army refers to its trainee officers as officer cadets (OCdt), who hold no authority over other ranks (except when appointed to carry out a role as part of training). OCdts are referred to as Mister/Miss until the completion of the early stages of their training, thereafter non-officers will refer to him/her as Sir/Ma'am.

While Cadet has always been a rank of limited authority and prestige (cadets and US Navy midshipmen have no authority over commissioned personnel, warrants, or officers, only subordinate cadets), midshipman has historically been a rank with limited leadership responsibility, particularly in the Royal Navy. This tradition was continued by the US Navy after its original adoption of the rank, but now US Navy midshipmen are limited in the same manner as cadets in the other US services. Additionally, US Marine officers in training are also midshipmen, trained and educated alongside their naval counterparts, and wear distinctive insignia to indicate their branch of service.

Note: US Coast Guard Academy students are referred to as cadets, while those attending the military branch's Officer Candidate School (OCS) are officer candidates.

In the US an alternative to spending four years as a cadet or midshipmen is for college graduates with a four-year degree to attend Officer Candidate School, an intensive twelve week training course designed to convert college graduates into military officers. Each service has at least one, and usually several, OCS facilities. Students at these programs are called officer candidates.

Warrant officers
Warrant officers (as receiving authority by virtue of a warrant) are a hybrid rank treated slightly differently in each country and/or service. WOs may either be effectively senior non-commissioned officers or an entirely separate grade between commissioned and non-commissioned officers, usually held by specialist personnel.

In the United States, warrant officers are appointed by warrant then commissioned by the President of the United States at the rank of chief warrant officer. Warrant Officers range from W01-CW5. A Warrant Officer is not a Chief Warrant Officer until they reach W2.

Enlisted personnel
Enlisted personnel are personnel below commissioned rank and make up the vast majority of military personnel. They are known by different names in different countries, such as other ranks (ORs) in the United Kingdom and some Commonwealth countries, and non-commissioned members (NCMs) in Canada.

Non-commissioned officers
Non-commissioned officers (NCOs) are enlisted personnel, under the command of an officer, granted delegated authority to supervise other military members or assigned significant administrative responsibilities. They are responsible for the care and direct control of junior military members, often functioning in the smaller field units as executive officers.

Even the most senior NCO officially ranks beneath the most junior commissioned officer or warrant officer. However, most senior NCOs have more experience, possibly including combat, than junior officers. In many armies, because junior officers have a great amount of responsibility and authority but little operational experience, they are paired with senior NCO advisers. In some organizations, senior NCOs may have formal responsibility and informal respect beyond that of junior officers, but less than that of warrant officers. Many warrant officers come from the ranks of mid-career NCOs. In some countries warrant ranks replace senior enlisted ranks.

NCO ranks typically include a varying number of grades of sergeant and corporal (Air Force, Army and Marines), or chief petty officer and petty officer (Navy and Coast Guard). In many navies the term rate is used to designate specialty, while rank denotes paygrade.

In some countries warrant officers come under the non-commissioned officer branch (senior non-commissioned officers).

Other enlisted ranks
Personnel with no command authority usually bear titles such as private, airman/aircraftman, or seaman (starting with seaman recruit in the United States Navy and Coast Guard). In the United States Marine Corps individuals of all ranks regardless of command status may be referred to as "marine". In some countries and services, personnel in different branches have different titles. These may have a variety of grades, such as private first class, but these usually only reflect variations in pay, not increased authority. These may or may not technically be ranks, depending on the country and/or service. Each rank gives the individual an indication of how long and how well they have served in combat and training.

Appointment
Appointment refers to the instrument by virtue of which the person exercises his or her authority. Officers are appointed by a Royal Commission in most monarchies or a Presidential Commission in many other countries. In the Commonwealth, warrant officers hold a Royal or Presidential Warrant. In the United States, officers are appointed by the president, with the advice and consent of the United States Senate. Most officers are approved en bloc by voice vote, but flag officers are usually required to appear before the Armed Services Committee and answer questions to the satisfaction of its members, prior to a vote on their commission.

NCOs are appointed by an instrument of appointment, a written document, often a certificate, usually from the service head. Entry into service is often referred to as enlistment throughout the English speaking world, even in countries where soldiers do not technically enlist.

Sometimes personnel serve in an appointment which is higher than their actual rank. For instance, commodore used to be an appointment of captain in the Royal Navy and lance corporal used to be an appointment of private in the British Army.

Types of rank
There are a number of different forms of rank; from highest to lowest degree, they are:
 * Substantive or permanent rank is the fully paid and confirmed rank.
 * War substantive rank is a confirmed rank only held for the duration of that war.
 * Temporary rank is usually granted for a specific task or mission. The holder holds the rank while occupying that position. Despite the name, temporary rank may be held for a considerable period of time, perhaps even years. In wartime, temporary ranks are often common. In the United Kingdom, the rank of brigadier was long considered a temporary rank; while its holder was addressed as "brigadier," he would retain the substantive rank of colonel or lieutenant-colonel.

After a war, regular serving members of the military holding war substantive or temporary rank often revert to their former, substantive rank and all others often end their service. However, the holder may be granted permission to permanently retain the rank they held when the conflict ended.


 * Acting rank is where the holder assumes the pay and allowances appropriate to the acting rank, but a higher commanding officer may revert the holder to previous rank held. This is normally for a short period of time while the permanent occupant of the office is absent.
 * Brevet rank is a temporary rank, often honorary, without the pay and allowances appropriate to the rank. It was sometimes used by penurious governments to reduce costs.
 * Local rank is a form of temporary rank restricted to a specific location instead of a specific duty.
 * Honorary rank, often granted on retirement, treats the rank as if it were substantive, but usually does not grant a corresponding wage or pension increase.

Rank and unit size
To get a sense of the practical meaning of these ranks—and thus to be able to compare them across the different armed services, different nations, and the variations of titles and insignia—an understanding of the relative levels and sizes of each command will be helpful. The ranking and command system used by U.S. Marine ground forces or U.S. Army infantry units can serve as a template for this purpose. It should be remembered that different countries will often use their own systems that do not match the presentation here.

Under this system, starting from the bottom and working up, a corporal leads a fireteam consisting of three other individuals. A sergeant leads a squad consisting of three fireteams. As a result, a full squad numbers 13 individuals. Squads usually have numbered designations (e.g., 1st Squad).

Generally, in most armies and marine units, a lieutenant or equivalent rank leads a platoon, which can consist of three or four squads. For example, in U.S. Marine infantry units, rifle platoons usually consist of three rifle squads of 13 men each, with a Navy corpsman, the platoon leader, and a platoon sergeant (i.e., a staff sergeant who serves as second-in-command). An infantry platoon can number from 42 to 55 individuals, depending on the service. Platoons are usually numbered (e.g., 1st Platoon) or named after their primary function (e.g., Service Platoon).

A captain or equivalent rank commands a company, usually consisting of four platoons (three line platoons and one heavy weapons platoon). His headquarters can include a first sergeant and as many as seven others. As such, a company can comprise from roughly 175 to 225 individuals. Equivalent units also commanded by captains are batteries (for field artillery units) and detachments. In English speaking countries, a company (or troop in the cavalry, and battery in the artillery) is usually designated by a letter (e.g., A Company). In non-English speaking countries, they are usually numbered. In most Commonwealth armies a company is commanded by a major, assisted by a captain.

A lieutenant colonel or equivalent rank commands a battalion or a squadron, often consisting of four companies, plus the various members of his headquarters. A battalion is around 500–1,500 men and usually consists of between two and six companies.

A colonel or equivalent commands a regiment or group, often consisting of four battalions (for an Infantry unit) or five to six air groups (for a wing). Battalions and regiments are usually numbered, either as a separate battalion or as part of a regimental structure (e.g., 1-501st Infantry in the US Army).

In these latter, abstractions cease to be helpful and it becomes necessary to turn to an actual unit. The 1st Battalion of the 1st Marine Regiment of the 1st Marine Division of the I Marine Expeditionary Force consists of three infantry companies, one weapons company, and one headquarters and service company. Above that, the 1st Marine Regiment (aka First Marines) consists of four such battalions and one headquarters company. Marine Air Control Group 18 of 1st Marine Air Wing of the III Marine Expeditionary Force consists of four squadrons, one battery, and one detachment, a mix of different-sized units under a regimental equivalent-sized unit.

The next level has traditionally been a brigade, commanded by a brigadier general, and containing two or more regiments. But this structure is considered obsolete today. At the present time, in the U.S. Army, a brigade is roughly equal to or a little larger than a regiment, consisting of three to seven battalions. Strength typically ranges from 1,500 to 3,500 personnel. In the U.S. Marines, brigades are only formed for certain missions. In size and nature they are larger and more varied collections of battalions than is common for a regiment, fitting them for their traditional role as the smallest formation able to operate independently on a battlefield without external logistical tactical support. Brigades are usually numbered (e.g., 2nd Brigade).

The level above regiment and brigade is the division, commanded by a major general and consisting of from 10,000 to 20,000 persons. The 1st Marine Division, for example, is made up of four marine regiments (of the type described above), one assault amphibian battalion, one reconnaissance battalion, two light armored reconnaissance battalions, one combat engineer battalion, one tank battalion, and one headquarters battalion—totalling more than 19,000 marines. (Within the headquarters battalion are one headquarters company, one service company, one military police company, one communications company, and one truck company.) An equivalent elsewhere within the same marine expeditionary force (MEF) might be a MEF logistics group (MLG) - which is not a regimental-sized unit (as the word "group" implies), but rather a large support unit consisting of several battalions of support personnel. Divisions are normally numbered, but can be named after a function or personage.

Considering such a variety of units, the command sizes for any given rank will vary widely. Not all units are as troop intensive as infantry forces need to be. Tank and artillery crews, for example, involve far fewer personnel. Numbers also differ for non-combat units such as quartermasters, cooks, and hospital staff. Beyond this, in any real situation, not all units will be at full strength and there will be various attachments and detachments of assorted specialists woven throughout the system.

The 1st Marine Division is part of the I Marine Expeditionary Force, which also includes the 3rd Marine Air Wing, 1st Marine Logistics Group, 1st Marine Expeditionary Brigade (as required), three marine expeditionary units (featuring helicopter groups), and a battalion-sized marine air ground task force. In the U.S. Marine Corps there are three marine expeditionary forces.

In the U.S. Army, the level above division is called a corps instead of an expeditionary force. It is commanded by a lieutenant general. In many armies, a corps numbers around 60,000, usually divided into three divisions. Corps (and similar organizations) are normally designated with roman numerals and their nationality when operating in a combined (international) force, e.g. V (US) Corps, VIII (ROK) Corps, II MEF, I Canadian Corps.

During World War II, due to the large scale of combat, multiple corps were combined into armies commanded in theory by a general (four stars), but often by a lieutenant general (three stars), and comprising as many as 240,000 troops. Armies are numbered by spelled-out numerals or functional titles, using their nationality in "combined" forces (e.g., Eighth US Army, Third ROK Army, British Army of the Rhine). These were in their turn formed into army groups, these being the largest field organization handled by a single commander in modern warfare. Army groups included between 400,000 and 1,500,000 troops. Army groups received Arabic numeral designations and national designations when combined.

These examples illustrate a standard that holds true all over the world and throughout military history, namely that higher rank generally implies command of larger units in a nested system of ranks and commands. The specific size of a command for any given rank will, however, depend on the task the unit performs, the nature of weapons used, and the strategies of warfare.