Jail codes, also known as inmate codes, include avoiding collaboration with prison authorities, not stealing from other inmates and not gambling. Jail codes are the informal rule, values and cultural norms that govern relationships among the imprisoned.
Jail or inmate codes are a major aspect of the subculture that develops between inmates inside prison. Some prisoners believe that those who ignore this advice become mules, or inmates responsible for smuggling drugs into the prisons, or who are otherwise exploited by fellow prisoners. Another rule that governs the behavior of inmates is "maintain yourself," meaning that prisoners are not to show any signs of emotion or weakness around other inmates.