A gang is defined here as a group of individuals who associate on a continuous basis for a designated purpose, usually in the form of criminal activity including robbery, assaults, and drug trafficking. Individuals often join gangs as a means of recognition or identity, protection, fellowship, intimidation, or criminal access. This manual covers many types of gangs, including those whose members are predominantly Hispanic, Black, Asian, or Cuban. Other chapters discuss female involvement with active street gangs, prison inmate gangs, and outlaw motorcycle gangs. The characteristics of each gang, including hand signs, monikers, colors, and other identifying marks, are described.