New York Codes, Rules and Regulations
Title 2 - DEPARTMENT OF AUDIT AND CONTROL
Chapter I - Audit Of Revenues And Accounts Payable From State Funds And Funds Under Its Control
Part 16 - Field Audit
Section 16.7 - Cafeterias and commissaries

(a) Accounting records shall be kept on an accrual basis in order to reflect properly the assets and liabilities and to determine the profit or loss from operations. This requirement is especially necessary where the activity must be operated on a self-sustaining basis, so that the price of goods sold shall be sufficient to defray all cost. A physical inventory shall be taken at the close of each fiscal year.

(b) Receipts shall be controlled, wherever practicable, through cash registers, or by the use of bound press-numbered receipt books or tickets. Expenditures shall be supported by invoices or vouchers approved by an authorized person.