A flag is a piece of fabric (most often rectangular or quadrilateral) with a distinctive design that is used as a symbol, as a signaling device, or as decoration. The term flag is also used to refer to the graphic design employed, and flags have since evolved into a general tool for rudimentary signalling and identification, especially in environments where communication is similarly challenging (such as the maritime environment where semaphore is used). National flags are patriotic symbols with varied wide-ranging interpretations, often including strong military associations due to their original and ongoing military uses. Flags are also used in messaging, advertising, or for other decorative purposes. The study of flags is known as vexillology, from the Latin word vexillum, meaning flag or banner.
Due to the use of flags by military units, 'flag' is also used as the name of some military units. A flag (Arabic) is equivalent to a brigade in Arab countries, and in Spain, a flag (Spanish: bandera) is a battalion-equivalent in the Spanish Legion.
This section relies largely or entirely on a single source. (May 2014)
In antiquity, field signs or standards were used in warfare that can be categorized as vexilloid or 'flag-like'. Examples include the Sassanid battle standard Derafsh Kaviani, and the standards of the Roman legions such as the eagle of Augustus Caesar's Xth legion, or the dragon standard of the Sarmatians; the latter was let fly freely in the wind, carried by a horseman, but judging from depictions it was more similar to an elongated dragon kite than to a simple flag.
During the High Middle Ages, flags came to be used primarily as a heraldic device in battle, allowing more easily to identify a knight than only from the heraldic device painted on the shield. Already during the high medieval period, and increasingly during the Late Middle Ages, city states and communes such as those of the Old Swiss Confederacy also began to use flags as field signs. Regimental flags for individual units became commonplace during the Early Modern period.
During the peak of the age of sail, beginning in the early 17th century, it was customary (and later a legal requirement) for ships to carry flags designating their nationality; these flags eventually evolved into the national flags and maritime flags of today. Flags also became the preferred means of communications at sea, resulting in various systems of flag signals; see, International maritime signal flags.
Use of flags outside of military or naval context begins only with the rise of nationalist sentiment by the end of the 18th century; the earliest national flags date to that period, and during the 19th century it became common for every sovereign state to introduce a national flag.
One of the most popular uses of a flag is to symbolize a nation or country. Some national flags have been particularly inspirational to other nations, countries, or subnational entities in the design of their own flags. Some prominent examples include:
It is said that the Dutch Tricolour has inspired many flags but most notably those of Russia, New York City, and South Africa (the 1928-94 flag as well the current flag). As the probable inspiration for the Russian flag, it is the source too for the Pan-Slavic colours red, white and blue, adopted by many Slavic states and peoples as their symbols; examples are Slovakia, Serbia, and Slovenia.
National flag designs are often used to signify nationality in other forms, such as flag patches.
A civil flag is a version of the national flag that is flown by civilians on non-government installations or craft. The use of civil flags was more common in the past, in order to denote buildings or ships that were not manned by the military. In some countries the civil flag is the same as the war flag or state flag, but without the coat of arms, such as in the case of Spain, and in others it's an alteration of the war flag.
Other countries' armed forces (such as those of the United States or Switzerland) use their standard national flag. The Philippines' armed forces may use their standard national flag, but during times of war the flag is turned upside down. Bulgaria's flag is also turned upside down during times of war. These are also considered war flags, though the terminology only applies to the flag's military usage.
Four distinctive African flags currently in the collection of the National Maritime Museum in Britain were flown in action by Itsekiri ships under the control of Nana Olomu during conflict in the late 19th century. One is the flag generally known as the Benin flag and one is referred to as Nana Olomu's flag.
Flags are particularly important at sea, where they can mean the difference between life and death, and consequently where the rules and regulations for the flying of flags are strictly enforced. A national flag flown at sea is known as an ensign. A courteous, peaceable merchant ship or yacht customarily flies its ensign (in the usual ensign position), together with the flag of whatever nation it is currently visiting at the mast (known as a courtesy flag). To fly one's ensign alone in foreign waters, a foreign port or in the face of a foreign warship traditionally indicates a willingness to fight, with cannon, for the right to do so. As of 2009, this custom is still taken seriously by many naval and port authorities and is readily enforced in many parts of the world by boarding, confiscation and other civil penalties.
In some countries yacht ensigns are different from merchant ensigns in order to signal that the yacht is not carrying cargo that requires a customs declaration. Carrying commercial cargo on a boat with a yacht ensign is deemed to be smuggling in many jurisdictions. There is a system of international maritime signal flags for numerals and letters of the alphabet. Each flag or pennant has a specific meaning when flown individually. As well, semaphore flags can be used to communicate on an ad hoc basis from ship to ship over short distances. Traditionally, a vessel flying under the courtesy flag of a specific nation, regardless of the vessel's country of registry, is considered to be operating under the law of her 'host' nation.
Another category of maritime flag flown by some United States Government ships is the distinguishing mark. Although the United States Coast Guard has its own service ensign, all other U.S. Government ships fly the national ensign their service ensign, following United States Navy practice. To distinguish themselves from ships of the Navy, such ships historically have flown their parent organisation's flag from a forward mast as a distinguishing mark. Today, for example, commissioned ships of the National Oceanic and Atmospheric Administration (NOAA) fly the NOAA flag as a distinguishing mark.
Flags are usually rectangular in shape (often in the ratio 2:3, 1:2, or 3:5), but may be of any shape or size that is practical for flying, including square, triangular, or swallow tailed. A more unusual flag shape is that of the flag of Nepal, which is in the shape of two stacked triangles. Other unusual flag shapes include the flag of Ohio and the flag of Tampa.
Many flags are dyed through and through to be inexpensive to manufacture, such that the reverse side is the mirror image of the obverse (front) side, generally the side displayed when the flag is flying from the observer's point of view from left, the side of the pole, to right. This presents two possibilities:
Some complex flag designs are not intended for through and through implementation, requiring separate obverse and reverse sides if made correctly. In these cases there is a design element (usually text) which is not symmetric and should be read in the same direction, regardless of whether the hoist is to the viewer's left or right. These cases can be divided into two types:
Common designs on flags include crosses, stripes, and divisions of the surface, or field, into bands or quarters--patterns and principles mainly derived from heraldry. A heraldic coat of arms may also be flown as a banner of arms, as is done on both the state flag of Maryland and the flag of Kiribati.
The de jure flag of Libya under Muammar Gaddafi, which consisted of a rectangular field of green, was for a long period the only national flag using a single colour and no design or insignia. However, other historical states have also used flags without designs or insignia, such as the Soviet Republic of Hungary, whose flag was a plain field of red.
Colours are normally described with common names, such as "red", but may be further specified using colorimetry.
The largest flag flown from a flagpole worldwide, according to Guinness World Records, is the flag of Mexico flown in Piedras Negras, Mexico. This flag was about 2,058 m2 (22,150 sq ft). The largest flag ever made was the flag of Qatar; the flag, which measures at 101,978 m2 (1,097,680 sq ft), was completed in December 2013 in Doha.
The general parts of a flag are: canton--the upper inner section of the flag; field or ground--the entire flag except the canton, and the field and hoist ends; fly end--the furthest edge from the hoist end; and hoist end--the edge used to attach the flag to the hoist.
Vertical flags are sometimes used in lieu of the standard horizontal flag in central and eastern Europe, particularly in the German-speaking countries. This practice came about because the relatively brisk wind needed to display horizontal flags is not common in these countries.
The standard horizontal flag (no. 1 in the preceding illustration) is nonetheless the form most often used even in these countries.
The vertical flag (German: Hochformatflagge or Knatterflagge; no. 2) is a vertical form of the standard flag. The flag's design may remain unchanged (No. 2a) or it may change, e.g. by changing horizontal stripes to vertical ones (no. 2b). If the flag carries an emblem, it may remain centered or may be shifted slightly upwards.
The vertical flag for hoisting from a beam (German: Auslegerflagge or Galgenflagge; no. 3) is additionally attached to a horizontal beam, ensuring that it is fully displayed even if there is no wind.
The vertical flag for hoisting from a horizontal pole (German: Hängeflagge; no. 4) is hoisted from a horizontal pole, normally attached to a building. The topmost stripe on the horizontal version of the flag faces away from the building.
The vertical flag for hoisting from a crossbar or banner (German: Bannerflagge; no. 5) is firmly attached to a horizontal crossbar from which it is hoisted, either by a vertical pole (no. 5a) or a horizontal one (no. 5b). The topmost stripe on the horizontal version of the flag normally faces to the left.
Flags can play many different roles in religion. In Buddhism, prayer flags are used, usually in sets of five differently coloured flags. Many national flags and other flags include religious symbols such as the cross, the crescent, or a reference to a patron saint. Flags are also adopted by religious groups and flags such as the Jain flag, Sikh flag, sindhi flag and the Christian flag are used to represent a whole religion.
As languages rarely have a flag designed to represent them, it is a common but unofficial practice to use national flags to identify them. The practice is deprecated because it is often considered insulting and because flags tend to evoke feelings other than the intended meaning. Examples of such use include:
Though this can be done in an uncontroversial manner in some cases, this can easily lead to some problems for certain languages:
In this second case, common solutions include symbolising these languages by:
Thus, on the Internet, it is common to see the English language associated with the flag of the United Kingdom, or sometimes the flag of England, the flag of the United States or a U.S.-UK mixed flag, usually divided diagonally.
Since many flags have a simple design, there is bound to be cases of flags with similar designs. From 1948 to 1989, the flag of Romania had an insignia in the middle of the tricolour flag. In 1989 the insignia was removed, reverting Romania's flag back to an earlier version. This version matched the design which had been adopted by Chad in 1959. This has concerned the Chadian government, and in 2004 they requested that the United Nations should consider it an issue. In response, the Romanian President Ion Iliescu stated to the media, "The tricolour belongs to us. We will not give up the tricolour".
In certain cases, flag similarities are not coincidental, but the result of a conscious choice.
The Pan-Arab colours black, white, green, and red are first known from the flag of the Arab Revolt in 1916. The colours were intended to represent certain Arab dynasties. Countries currently using flags with the Pan-Arab colours include Jordan, Kuwait, Palestine and Sudan.
The tricolor flag of Russia, inspired by the flag of the Netherlands, was introduced in the late 17th century. Based on this flag, the first Pan-Slav congress defined the Pan-Slavic colours red, blue and white. Among former and current countries beside Russia using flags with these colours, are Yugoslavia and the successor states Croatia, Serbia and Slovenia as well as the Czech Republic and Slovakia.
The oldest flag of the Nordic countries is the flag of Denmark with a description dating from 1748. The design has a cross symbol in a rectangular field, with the center of the cross shifted towards the hoist. This basic design is called Nordic cross and has been adopted by the other Nordic countries Finland, Iceland, Norway and Sweden as well as the dependent territories of Faroe Islands and Åland. Similar flags are also used as regional flags, most prominently the semi-official flag of Scania. The design has also been used outside the Nordic countries in order to underline a cultural connection. Examples are Shetland and Orkney.
Liberia was founded by freed African-American and ex-Caribbean slaves as settlers from the United States and the Caribbean. When Liberia gained independence in 1847, the flag of the new state was modelled on the national flag of the United States, although the symbolism of the elements were differently interpreted.
The Red Cross on white background as a protection symbol was declared at the First Geneva Convention in 1864. The emblem was formed by reversing the colours of the Swiss flag out of respect to Switzerland.
Because of their ease of signalling and identification, flags are often used in sports.
Social and political movements have adopted flags, to increase their visibility and as a unifying symbol.
The socialist movement uses red flags to represent their cause. The anarchist movement has a variety of different flags, but the primary flag associated with them is the black flag. In the Spanish civil war, the anarchists used the red-and-black bisected flag. In the 20th century, the rainbow flag was adopted as a symbol of the LGBT social movements. Its derivatives include the Bisexual pride and transgender pride flags.
Some of these political flags have become national flags, such as the red flag of the Soviet Union and national socialist banners for Nazi Germany. The present Flag of Portugal is based on what had been the political flag of the Portuguese Republican Party previous to the 5 October 1910 revolution which brought this party to power.
Some disability advocacy groups have adopted flags to raise awareness of their causes.
When the World Federation of the Deaf adopted its own flag, this action caused some controversy within the deaf community due to the popularity of another flag which was already being flown by many deaf people and related organisations.
Flags are often representative of an individual's affinity or allegiance to a country, team or business and can be presented in various ways. A popular trend that has surfaced revolves around the idea of the 'mobile' flag in which an individual displays their particular flag of choice on their vehicle. These items are commonly referred to as car flags and are usually manufactured from high strength polyester material and are attached to a vehicle via a polypropylene pole and clip window attachment.
In Australia, Canada, New Zealand, the Philippines, and the United Kingdom, a pair of red-yellow flags is used to mark the limits of the bathing area on a beach, usually guarded by surf lifesavers. If the beach is closed, the poles of the flags are crossed. The flags are coloured with a red triangle and a yellow triangle making a rectangular flag, or a red rectangle over a yellow rectangle. On many Australian beaches there is a slight variation with beach condition signaling. A red flag signifies a closed beach (in the UK also other dangers), yellow signifies strong current or difficult swimming conditions, and green represents a beach safe for general swimming. In Ireland, a red and yellow flag indicates that it is safe to swim; a red flag that it is unsafe; and no flag indicates that there are no lifeguards on duty. Blue flags may also be used away from the yellow-red lifesaver area to designate a zone for surfboarding and other small, non-motorised watercraft.
Reasons for closing the beach include:
A surf flag exists, divided into four quadrants. The top left and bottom right quadrants are black, and the remaining area is white.
Signal flag "India" (a black circle on a yellow square) is frequently used to denote a "blackball" zone where surfboards cannot be used but other water activities are permitted.
Railways use a number of coloured flags. When used as wayside signals they usually use the following meanings (exact meanings are set by the individual railroad company):
At night, the flags are replaced with lanterns showing the same colours.
Flags displayed on the front of a moving locomotive are an acceptable replacement for classification lights and usually have the following meanings (exact meanings are set by the individual railroad company):
A flagpole, flagmast, flagstaff, or staff can be a simple support made of wood or metal. If it is taller than can be easily reached to raise the flag, a cord is used, looping around a pulley at the top of the pole with the ends tied at the bottom. The flag is fixed to one lower end of the cord, and is then raised by pulling on the other end. The cord is then tightened and tied to the pole at the bottom. The pole is usually topped by a flat plate or ball called a "truck" (originally meant to keep a wooden pole from splitting) or a finial in a more complex shape. Very high flagpoles may require more complex support structures than a simple pole, such as a guyed mast.
Since 23 September 2014, the tallest free-standing flagpole in the world is the Jeddah Flagpole in Saudi Arabia at a height of 171 m (561 ft), exceeding the former record holder the Dushanbe Flagpole in Tajikistan (height: 165 m, 541 ft), National Flagpole in Azerbaijan (height: 162 m, 531 ft) and the North Korean flagpole at Kij?ng-dong (height: 160 m, 520 ft). The flagpole in North Korea actually is a radio tower with a flag on top. Besides two flagpoles mentioned above, the previous six world-record flagpoles were all built by American company Trident Support, and the rest are in: Ashgabat, Turkmenistan: 436 feet; Aqaba, Jordan: 433 feet; Amman, Jordan 417 feet; and Abu Dhabi, United Arab Emirates: 404 feet. 
The current tallest flagpole in the United States (and the tallest flying an American flag) is the 400-foot (120 m) pole completed before Memorial Day 2014 and custom-made with an 11-foot (3.4 m) base in concrete by wind turbine manufacturer Broadwind Energy. It is situated on the north side of the Acuity Insurance headquarters campus along Interstate 43 in Sheboygan, Wisconsin, and is visible from Cedar Grove. The pole can fly a 220-pound flag for in light wind conditions and a heavier 350-pound flag in higher wind conditions.
Flagpoles can be designed in one piece with a taper (typically a steel taper or a Greek entasis taper), or be made from multiple pieces to make them able to expand. In the United States, ANSI/NAAMM guide specification FP-1001-97 covers the engineering design of metal flagpoles to ensure safety.
Flagpole of modest size, with simple truck
New Caledonia has two official flags, flown here in Nouméa, the capital city, on a single flagpole with a crossbar.
Hoisting the flag is the act of raising the flag on the flagpole. Raising or lowering flags, especially national flags, usually involves ceremonies and certain sets of rules, depending on the country, and usually involve the performance of a national anthem.
A flag-raising squad is a group of people, usually troops, cadets, or students, that marches in and brings the flags for the flag-hoisting ceremony. Flag-hoisting ceremonies involving flag-raising squads can be simple or elaborate, involving large numbers of squads. Elaborate flag-hoisting ceremonies are usually performed on national holidays.
Semaphore is a form of communication that utilizes flags. The signalling is performed by an individual using two flags (or lighted wands), the positions of the flags indicating a symbol. The person who holds the flags is known as the signalman. This form of communication is primarily used by naval signallers. This technique of signalling was adopted in the early 19th century and is still used in various forms today.
The colours of the flags can also be used to communicate. For example; a white flag means, among other things, surrender or peace, a red flag can be used as a warning signal, and a black flag can mean war, or determination to defeat enemies.
Orientation of a flag is also used for communication, though the practice is rarely used given modern communication systems. Raising a flag upside-down was indicative that the raising force controlled that particular area, but that it was in severe distress.
When blown by the wind, flags are subject to wave-like motions that grow in amplitude along the length of the flag. This is sometimes ascribed to the flag pole giving vortex shedding; however, flags that are held by lanyards also can be seen to flap.
Art. 18. Out of respect to Switzerland the heraldic emblem of the red cross on a white ground, formed by the reversal of the federal colors, is continued as the emblem and distinctive sign of the sanitary service of armies.