Gang sign

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.

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. 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 at war with another gang, they may visit locations the rival gang has already made their mark upon, crossing out the names of enemies they have killed, or simply covering up the rival. This is also known as a "cross out".

The original usage of hand sign can be traced back to the Pilgrims. 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", "page", "gang walk") 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.

...
Wikipedia