Michigan Compiled Laws, Chapter 801. Jails and Workhouses § 801.51

(a) “County jail” means a facility operated by a county for the physical detention and correction of persons charged with or convicted of criminal offenses and ordinance violations, persons found guilty of civil or criminal contempt, and juveniles detained by court order.

(b) “Department of corrections” means the state department of corrections.

(c) “Prisoner” means a person who is currently being physically detained in a county jail.

(d) “Rated design capacity” means the actual available bed space of the general population of a county jail as determined by the department of corrections.