The inmate code is:

A. the set of rules for inmate behavior established by prison officials.

B. an informal set of rules of inmate behavior that is part of the prison culture.

C. a secret language inmates use to communicate with each other in the presence of guards or other officials.

D. something that has existed in earlier prisons but is relatively rare in contemporary correctional institutions.

i think C but am not sure

3 answers

it could be B.
http://en.wikipedia.org/wiki/Inmate_Code
Inmate Code refers to the rules and values that have developed among prisoners inside prisons social systems.[1] The inmate code helps define an inmate's image as a model prisoner. The code helps to emphasize unity of prisoners against correctional workers.
This code highlights the reasons why "rehabilitation" is often so difficult to achieve.