Section 1.705 - Supersession and modification(a) If a D&F is superseded by another D&F, that action shall not render invalid any action taken under the original D&F prior to the date of its supersession.(b) The contracting officer need not cancel the solicitation if the D&F, as modified, supports the contract action.50 FR 1726, Jan. 11, 1985, and 50 FR 52429, Dec. 23, 1985, as amended at 67 FR 13053 , Mar. 20, 2002