Vexillologists

Graham Bartram, Chief Vexillologist of the Flag Institute, and Secretary-General for Congresses of FIAV

William Crampton, founder of the Flag Institute

Marc Leepson, author of Flag: An American Biography

Michel Lupant, current president of the FIAV

Ottfried Neubecker, most important German vexillologist, author of the German navy Flaggenbuch of 1939

George H. Preble, author in 1872 of the influential, if lore-filled, History of the American Flag

Rudolf Siegel, author of the influential book Die Flagge, published in 1912

Whitney Smith, founder of the Flag Research Center, editor of the Flag Bulletin, and coiner of the word "Vexillology" in 1957

Railway flags

Railways use a number of colored flags. When used as wayside signals they usually use the following meanings (exact meanings are set by the individual railroad company):

red = stop
yellow = proceed with care
green or white or blue = proceed.

A blue flag on the side of a locomotive means that it should not be moved because someone is working on it (or on the train attached to it). A blue flag on a track means that nothing on that track should be moved. The flag can only be removed by the person or group that placed it.
At night, the flags are replaced with lanterns showing the same colors.

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):

white = extra (not on the timetable)
green = another section following
red = last section

Additionally, a railroad brakeman will typically carry a red flag to make his or her hand signals more visible to the engineer.

Railway signals are a development of railway flags.

Swimming flags

In Australia, New Zealand, 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 colored 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 signalling. A red flag signifies a closed beach (or, in the UK, some other danger), yellow signifies strong current or difficult swimming conditions, and green represents a beach safe for general swimming. 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:

no lifeguards in attendance
waves too strong
dangerous rip
sharks
tsunami

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.

Vexillographers

Emilio Aguinaldo, designer of the flag of the Philippines

Luis and Sabino Arana, designers of the Ikurriña (the flag of Basque Country, Spain)

Graham Bartram, designer of the flag of Tristan da Cunha and others

Manuel Belgrano, designer of the flag of Argentina

Ron Cobb, designer of the American Ecology Flag

John Eisemann, designer of the flag of the U.S. state of Ohio

Stephen Greeter (fictional), played by a chess piece in the fumetto Terror Island

Robert G. Heft, a designer of the 50-star canton for the American flag

Adolf Hitler, designer of the Reichskriegsflagge and his personal standard of Nazi Germany

Francis Hopkinson, designer (according to some historians) of the American flag
Sharif Hussein, designer of the flag of the Arab Revolt

Lu Hao-tung, designer of the Blue Sky with a White Sun flag of the Republic of China

John McConnell, designer of the Earth flag

Fredrik Meltzer, designer of the flag of Norway

Raimundo Teixeira Mendes, designer of the flag of Brazil

William Porcher Miles, designer of the battle flag of the Confederate States of America

Francisco de Miranda, designer of the flag of Venezuela

Friedensreich Hundertwasser, designer of the Koru Flag among others

Christopher Pratt, designer of the flag of the Canadian province of Newfoundland and Labrador

Betsy Ross, designer (according to legend) of the American flag

Gerard Slevin, former Chief Herald of Ireland reputed to have helped design the flag of the
European Union

Whitney Smith, designer of the flag of Guyana and other flags

George Stanley, designer of the flag of Canada

Robert Watt, designer of the Flag of Vancouver, British Columbia, Canada

Zeng Liansong, designer of the flag of the People's Republic of China

Flags in Sports

Because of their ease of signalling and identification, flags are often used in sports.
In American and Canadian football, referees use flags to indicate an error has been made in game play. The phrase used for such an indication is flag on the play. The flag itself is a small, weighted handkerchief, tossed on the field at the approximate point of the infraction; the intent is usually to sort out the details after the current play from scrimmage has concluded. In American football, the flag is usually yellow; in Canadian football, it is usually red.

In auto and motorcycle racing, racing flags are used to communicate with drivers. Most famously, a checkered flag of black and white indicates the end of the race, and victory for the leader. A yellow flag is used to indicate caution requiring slow speed and a red flag requires racers to stop immediately. A black flag is used to indicate penalties.

In Association football (soccer), linesmen carry small flags along the touch lines. They use the flags to indicate to the referee potential infringements of the laws, or who is entitled to possession of the ball that has gone out of the field of play, or, most famously, raise the flag overhead to indicate an offside offence. Officials called touch judges use flags for similar purposes in both codes of rugby.

In addition, fans of almost all sports wave flags in the stands to indicate their support for the participants. Many sports teams have their own flags, and, in individual sports, fans will indicate their support for a player by waving the flag of his or her home country.

In Gaelic football and Hurling a green flag is use to indictate a goal while a white flag is used to indicate a point

In Australian rules football, the goal umpire will wave two flags to indicate a goal and a single flag to indicate a point.

For safety, dive flags indicate the locations of underwater scuba divers.

Religious flags

Flags can play many different roles in religion. In Buddhism, prayer flags are used, usually in sets of of five differently colored 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 are used to represent a whole religion.

Shape and Design

Flags are usually rectangular in shape (often in the ratio 2:3 or 3:5), but may be of any shape or size that is practical for flying, including square, triangular, or swallowtailed. A more unusual flag shape is that of the flag of Nepal, which is in the shape of two stacked triangles.

Many flag merchants prey on unwary buyers by offering incorrect flags, such as with the wrong proportions, crudely drawn, or one-sided. Some reference materials alter the flag proportions so they look uniform, such as decades of editions of the annual World Almanac and Book of Facts.
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. This presents two possibilities:
If the design is symmetrical in an axis parallel to the flag pole, obverse and reverse will be identical despite the mirror-reversal.

If not, the obverse and reverse will present two variants of the same design, one with the hoist on the left, the other with the hoist on the right. This is very common and usually not disturbing if there is no text in the design.

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:
The same (asymmetric) design may be duplicated on both sides. Such flags can be manufactured by creating two identical through and through flags and then sewing them back to back, though this can affect the resulting combination's responsiveness to the wind. Depictions of such flags may be marked with the symbol , indicating the reverse is congruent to (rather than a mirror image of) the obverse.

Rarely, the reverse design may differ, in whole or in part, from that of the obverse. Examples are the national flag of Paraguay, the flag of the U.S. state of Oregon, and the historical national flag of the Soviet Union. Depictions of such flags may be marked with the symbol .


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 flag of Libya, which consists of a rectangular field of green, is the only national flag using a single color and no design or insignia.