A. All agencies of the borough which use supplies shall, either by or with the authorization of the department head under which the using agency operates, file with the purchasing agent requisitions or estimates of their requirements for supplies and contractual services in such manner, at such times, and for such future periods as the purchasing agent shall prescribe.

B. Unforeseen Requirements. A using agency shall not be prevented from filing, in the same manner, with the purchasing agent at any time, a requisition or estimate for any supplies and contractual services, the need for which was not foreseen when the detailed estimates were filed.

C. Revisory Power in Agent. The purchasing agent shall examine each requisition or estimate and shall have the authority to recommend revisions as to quantity, quality, or estimated cost.