There are hundreds of written and unwritten regulations that must be observed by inmates. Some are institutional regulations, but most are convict codes. Inmates learn these codes of conduct through extended schooling that takes place during periods of commitment, while serving sentences in juvenile hall (grammar school), youth authority (high school), and state and federal prisons (colleges and universities). This training is augmented by mentoring under gang "veteranos" (veterans) and OGs (Original Gangsters) in and out of custody. These systems vary, but most are dictated by the prison gang or threat group that represents the inmate's race.
I've always marveled at this irony. Young men who rebel against authority and parental control, who commonly hate school, hate memorizing verses and symbols, hate reading history, hate learning new languages, and hate participating in physical education, enjoy doing all these things for their prison gang leaders.
Some of these regulations can be compared to our own penal system. Among gang inmates, a gang member who acts or talks like a homosexual, dresses unacceptably or "sexually," or does any act in public that suggests a feminine side, will be disciplined by his peers.
I'll use this example to illustrate an inmate regulation. A Latino gang member sits with his peer inmates at the breakfast table in the mess hall. Bananas are served with his meal. The young unschooled Latino holds the banana with his left hand, peels the banana by pulling the peel down about half way with his right hand. He then raises the banana to his mouth and takes a big bite off the top of the banana. This is a misdemeanor violation of Latino etiquette.
In Latino gang culture, eating a banana or wiener by its end in this manner looks like the sexual act of oral sex. This unacceptable behavior in front of sexually supercharged inmates must be punished. The covert and underground inmate code of conduct has few fines, probation or demerit systems in place. Physical discipline is the general rule. The violator is rarely warned about his perceived mistake. He'll be treated normally until his peers have "held court" and determined a discipline appropriate to the crime. This system is sometimes called "marching," "check courting," or "discipline."