Criminal tattoos are a type of tattoos associated with criminals to show gang membership and record the wearer's personal history—such as their skills, specialties, accomplishments, incarceration, world view and/or means of personal expression. Tattoos are strongly empirically associated with deviance, personality disorders, and criminality. Certain tattoo designs have developed recognized coded meanings. The code systems can be quite complex, and because of the nature of what they encode, the designs of criminal tattoos are not widely recognized as such to outsiders.