A gang signal is a visual or verbal way gang members identify their affiliation. This can take many forms including slogans, tattoos, hand signs and colored clothing. Many of these, especially slogans and hand signs, have become part of popular culture. The wearer usually favors, or is in, that particular gang. With symbols, graffiti is a large symbol displayed on walls or trains.
Gangs have been present in the United States for a long period. The violent crime based gangs became present in the early 1900s. Gangs back in the 1920s differ from the gangs today. Back then the prevalent gangs were the Italian Mafia, the different families in particular cities were the divided crews. As time went on and as the United States were changing rapidly race became a big factor in creating the gangs that we know today. When blacks protested against the segregation they created gangs to become stronger. These groups evolved over time and grew larger and larger. Today there are over 33,000 different gangs in the United States including 1.4 million members. 
Tattoos have long been associated with gang membership, and connote the toughness desired by gang members as well as the permanence of gang affiliation. The designs used are frequently symbolic and represent particular deeds, such as murder. Burn-marks may also be a way of recognition to a gang or a gang member.
The gang symbols used in tattoos and graffiti are fairly involved and refer to the mythology and meaning that each gang may invent. For example, the Star of David represents the Folk Nation once led by a man known as King David. The six point star is also sometimes used by Crips. In addition, each point of the star represents a "value" of the "nation." Sureño, commonly associated with La Eme, use the numbers 13 and 3 to refer to themselves, referencing the fact that "M" is the 13th letter of the English alphabet.
Graffiti has also long been seen as a gang-related activity, and its use is closely connected to the fact that many gangs have particular areas that they always try to control. As above, the graffiti is often highly symbolic and may contain more information about the gang's activities, values, and their current opponents.
Most often, gangs spray graffiti to mark territory or send a threat to a rival gang. When a
The original usage of hand sign can be traced back to the Triads.They would use them as code not only to represent themselves, but to identify themselves to other members. "Throwing up" a gang sign (e.g., "Stacking," "walk"[clarification needed]) with the hands is one of the most known and obvious forms of "claiming." It is used in many situations where other identifiers may not be possible or appropriate, and it can also show that a gang member is in the area to "do business" as opposed to just passing through. Usually these signs are made by formation of the fingers on one or both hands to make some sort of symbol or letter. It can also serve to relay more specific information, such as what set they represent within a larger gang or in which activities they are currently taking part. Individual letters can be used to tell stories when flashed in rapid succession, each representing a word beginning with that letter. These signs, because they are displayed only when wanted (as opposed to the types of identifiers above), are usually the most consistent across various areas. Many of these hand signals are quite close to other common hand signs, and this can cause confusion among gang members, non-gang members, and anti-gang authorities. "Stacking" is also known as a "Page."
Another identifier that can be displayed only when desired is a gang handshake, which usually includes some component of the gang hand signs and/or other hand and finger symbols.
Clothing is a strong signal that all gangs show. The clothing gangs wear allows rival gangs to identify who is friend and who is foe. For example, the uniform for Hispanic gangs are standard and easily recognizable. Gangs such as the Latin Kings would wear long white T-shirts, baggy pants, and either a bandana or a hat, sometimes both. Black gang members are individualistic with their clothing. The gang would wear a specific clothing and certain accessories that would match their crew's colors. Two famous examples would be the rival gangs, the Bloods and the Crips. Members of the Bloods wear red shirts, bandanas, and other clothing to identify themselves as Bloods, while the Crips do likewise with blue. 
Bandanas can be worn in various types of colors and ways to signify what gang they are affiliated with. The most popular bandana colors are red, blue, black, white, grey, and yellow. It is typically worn on your head or in the left or right back pockets of gang members.
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