TM 10-5430-243-12&P 0034 00 Change 1 0034 00-2 Source Code.  The source code tells you how you get an item needed for maintenance, repair, or overhaul of an end item/equipment.  Explanations of source codes follow: Source Code Application/Explanation PA PB PC PD PE PF PG Stock items; use the applicable NSN to requisition/request items with these source codes.   They are authorized to the level indicated by the code entered in the 3^rd position of the SMR code. NOTE Items coded PC are subject to deterioration. KD KF KB Item with these codes are not to be requested/requisitioned individually.  They are part of a kit which is authorized to the maintenance level indicated in the 3^rd position of the SMR code.  The complete kit must be requisitioned and applied. MO – Made at unit/AVUM level MF – Made at DS/AVIM level MH – Made at GS level ML – Made at SRA MD – Made at depot Items with these codes are not to be requisitioned/requested individually.  They must be made from bulk material which is identified by the P/N in the DESCRIPTION AND USABLE ON CODE (UOC) column and listed in the bulk material group work package of 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 higher level, order the item from the higher level of maintenance. AO – Assembled by unit/AVUM level AF – Assembled by DS/AVIM level AH – Assembled by GS level 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 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 the next higher assembly.  (Refer to the NOTE below.) XB If an item is not available from salvage, order it using the CAGEC and P/N. XC Installation drawings, diagrams, instruction sheets, field service drawings; identified by manufacturer’s P/N. XD Item is not stocked.  Order an XD-coded item through normal supply channels using the CAGEC and P/N given, if no NSN is available.