A purchase order may be modified by using a form approved by the CCO. Each purchase order modification shall identify the order it modifies and shall contain an appropriate modification number.
The CCO may obtain a contractor's written acceptance of a purchase order modification if the written acceptance is determined by the CCO to be necessary to ensure the contractor's compliance and acceptance of the purchase order as modified.
D.C. Mun. Regs. tit. 8, r. 8-B3013