(a) Contract line items shall consist of four numeric digits 0001 through 9999. Do not use numbers beyond 9999. Within a given contract, the item numbers shall be sequential but need not be consecutive.

(b) The contract line item number shall be the same as the solicitation line item number unless there is a valid reason for using different numbers.

(c) Once a contract line item number has been assigned, it shall not be assigned to another, different, contract line item in the same contract.