Gangs use hand signs as a means of communication. Most often, hand signs are a way to issue a challenge or to throw out an insult. Many gang assaults start with the exchange of gang hand signs between rival gangs. This is sometimes referred to as "flashing" or "throwing" signs.

38--This version of 38 is formed using two hands. The thumb and first two fingers of each hand curve together to form two small "o"s--the "8." The ring and small fingers of both hands form the "3." The ring fingers touch, while the small fingers fan out to form the top and bottom of the "3."

Sometimes hand signs are a symbol of something significant to the gang such as "13" or "N." Gang hand signs can signify a gang name or acronym such "TOP" (Tiny Oriental Posse) or "QVO" (a corruption of the Spanish phrase, "Que Hubo," meaning, "What's happening?"). A rival gang would see this as a challenge. The QVO hand sign can be done with two hands. The first hand forms the "Q" by making a small "o" with the thumb and index finger. The remaining fingers stay together, forming the line that comes down from the "Q." The last 3 fingers of both hands touch together at the fingertips and form the "V." The thumb and index finger of the second hand form the "O."

A hand sign can be a direct threat such as "BK" (Blood Killer) or "CK" (Crip Killer). A Crip gang member would use the "BK" hand sign to mean "Kill a Blood." The small "o" formed by the thumb and index finger and the middle finger are supposed to resemble a lowercase letter "b." The last three fingers spread out and form the "k."