The answer to your inquiry may be found in DFARS subpart 208.70.

208.7000  Scope of subpart. This subpart prescribes policy and procedures for acquisition of items for which contracting responsibility is assigned to one or more of the departments/agencies or the General Services Administration.  Contracting responsibility is assigned through—
 
  (a)  The Coordinated Acquisition Program (commodity assignments are listed in PGI 208.7006 (DFARS/PGI view); or
 
  (b)  The Integrated Materiel Management Program (assignments are in DoD 4140.26-M, Defense Integrated Materiel Management Manual for Consumable Items).