(c) The agency head or designee shall employ procedures to ensure that requirements for service contracts are vetted and approved as a safeguard to prevent contracts from being awarded or administered in a manner that constitutes an unauthorized personal services contract. Contracting officers shall follow the procedures at PGI 237.503 , include substantially similar certifications in conjunction with service contract requirements, and place the certification in the contract file. The program manager or other official responsible for the requirement, at a level specified by the agency, should execute the certification. In addition, contracting officers and program managers should remain aware of the descriptive elements at FAR 37.104(d) to ensure that a service contract does not inadvertently become administered as a personal-services contract.