California Code, Penal Code - PEN § 5005

(a) The department shall maintain a canteen at an active prison or institution under its jurisdiction for the sale to incarcerated persons of toilet articles, candy, notions, and other sundries, and shall provide the necessary facilities, equipment, personnel, and merchandise for the canteen. The secretary shall specify what commodities shall be sold in the canteen. The sale prices of the articles offered for sale shall not exceed a 35-percent markup above the amount paid to the vendors.

(b) The department shall undertake to insure against damage or loss of canteen and handicraft materials, supplies, and equipment owned by the Inmate Welfare Fund as provided in Section 5006.

(c) The canteen operations at any prison or institution referred to in this section shall be audited biennially by the Department of Finance, and at the end of each intervening fiscal year, each prison or institution shall prepare a statement of operations. At least one copy of any audit report or statement of operations shall be posted at the canteen and at least one copy shall be available to incarcerated persons at the library of each prison or institution.

(d) This section shall remain in effect only until January 1, 2028, and as of that date is repealed.