TM 10-3930-653-14&P 3. Explanation of Columns (Sections II and III) (Con’t). (1) Source  Code.    The  source  code  tells  you  how  to  get  an  Item  needed  for  maintenance,  repair,  or overhaul of an end item/equipment.  Explanations of source codes follow: Code Application/Explanation .............................................................................................................................. .............................................................................................................................. .............................................................................................................................. NOTE Cannibalization or controlled exchange, when authorized, may be used as a source of supply for items with the above source codes, except for those source Change 1  C-2 Stocked items; use the applicable NSN to request/requisition items with these source codes.  They are authorized to the category indicated by the code entered in the 3rd position of the SMR code. **Items coded PC are subject to deterioration. Items with these codes are not to be requested/requisitioned individually.  They are part of a kit which is authorized to the maintenance category indicated in the 3rd position of the SMR Items with these codes are not to be requested/requisitioned individually.  They must be made from bulk materiel which is identified by the part number in the DESCRIPTION AND USABLE ON CODE (UOC) column and listed in the bulk materiel group of the repair parts list in this RPSTL.  If the item is authorized to you by the 3d position code of the SMR code, but the source code indicates it is made at a higher level, order the Items with these codes are not to be requested/requisitioned individually.  The parts that make up the assembled item must be requisitioned or fabricated and assembled at the level of maintenance indicted by the source code.  If the 3d position code of the SMR code authorizes you to replace the item, but the  source  code  indicates  that  the  item  is  assembled  at  a  higher