The constitution of a gang

1. A member may not be a homosexual. 

2. A member may not be an informant. 

3. A member may not be a coward. 

4. A member must not raise a hand against another member without sanction. 

5. A member must not show disrespect for any member’s family, including sex with another member’s wife or girlfriend. 

6. A member must not steal from another member. 

7. A member must not interfere with another member’s business activities. 

8. A member must not politic against another member or cause dissension within the organization. 

9. Membership is for life. 

10. Membership mandates assaulting/killing all drop outs. 

11. The Mexican Mafia comes first—even before your own family.

That is from the paper Governance and Prison Gangs (HT Marginal Revolution).