TM 11-5820-890-20P-1 2 (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 follows: 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 coded “XA” or those aircraft support items restricted by requirements of AR 750-1. 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 source code entered in the third position of the SMR code. NOTE Items coded PC are subject to deterioration. KD KF KB 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 third position of the SMR code. The complete kit must be requisitioned and applied. XA  —   Do not requisition an “XA” coded item. Order its next higher assembly. XB  —   If an “XB” item is not available from salvage, order it using the CAGEC and part number given. XC  —   Installation drawing, diagram, instruction sheet, 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 part number given, if no NSN is available. Items    with    these    codes    are    not    to    be    requested/requisitioned individually. They must be made from bulk material which 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. If the  item  is  authorized to  you  by  the  third  position  code  of the  SMR code, but the source code indicates it is made at a higher category, order the item from the higher category of maintenance. 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    category    of maintenance indicated by the source code. If the disposition code of the SMR code authorizes you to replace the item, but the source code indicates the item is assembled at a higher category, order the item from the higher category of maintenance. MO —   Made at org/   AVUM category MF  —   Made at DS/ AVIM category MH —   Made at GS category ML  —   Made at Spec- ialized Repair Activity (SRA) MD —   Made at Depot AO  —   Assembled by org/ AVUM category AF   —   Assembled by DS/ AVIM category AH  —   Assembled by GS category AL   —   Assembled by SRA AD  —   Assembled by Depot