See MP5301.601(a)(i).

The notice of award for the congressional defense committees shall be submitted to SAF/LLW no later than 35 days after contract award. Maintain proof of submission of award notification in the contract file. Contracting officers may use the DD 1279 as the basis for this notice; however, this notification does not take the place of the Announcement of Contract Award made in accordance with DFARS 205.303 and DAFFARS 5305.303 Announcement of Contract Awards.