0064 00 TM 10-1670-287-23&P Source Code. The source code tells you how to get an item needed for maintenance, repair, or  overhaul of an end item/equipment. Source codes are always the first and second positions of the  SMR code. Explanations of source codes follow:  SOURCE CODE  EXPLANATION  PA PB PC PD PE PF PG 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 3$^{rd}$ position of the SMR code.  KD KF KF Items with these codes are not to be requested/  requisitioned individually. They are part of a kit that is  authorized to the maintenance category indicated in  the 3$^{rd}$ position of the SMR code. The complete kit  must be requisitioned and applied.  MO – (Made at org/AVUM Level)  MF – (Made at DS/AVUM Level)  MH – (Made at GS Level)  ML – (Made at Specialized Repair Act (SRA))  MD – (Made at Depot)  Items with these codes are not to be  requested/requisitioned individually. They must be  made from bulk material that is identified by the part  number in the DESCRIPTION and USABLE ON  CODE (UOC) column and listed in the Bulk Material  group of the repair parts list in the RPSTL. If the item  is authorized to you by the 3$^{rd}$ position code of the  SMR code, but the source code indicates it is made at  a higher level, order the item from the higher level of  maintenance. AO – (Assembled by org/AVUM Level)  AF – (Assembled by DS/AVIM Level)  AH – (Assembled by GS Category)  AL – (Assembled by SRA)  AD – (Assembled by Depot)  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  indicated by the source code. If the 3$^{rd}$ position code  of the SMR code authorizes you to replace the item,  but the source code indicates the item is assembled  at a higher level, order the item from the higher level  of maintenance.  XA -  Do not requisition an XA-coded item. Order its next  higher assembly. (Also, refer to the NOTE below.) XB -  If and XB-coded item is not available from salvage,  order it using the CAGEC and the given part number.  XC -  The installation drawing, diagram, instruction sheet,  and field service drawing that is identified by  manufacturers part number.  XD -  Item is not stocked. Order an XD-coded item through  normal supply channels using the CAGEC and the  part number given, if no NSN is available.  0064 00-2 