TM 9-6115-658-13&P C-4 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 Stock items; use the applicable NSN PB to requisition/request items with these PC source codes.  They are authorized to PD the level indicated by the code entered PE in the 3^rd position of the SMR code. PF PG NOTE Items coded PC are subject to deterioration. Items with these codes are not to be KD requested/requisitioned individually. KF They are part of a kit which is auth- KB orized to the maintenance level indicated in the 3^rd position of the SMR code.  The completed kit must be requisitioned and applied. MO-Made at unit/ Items with these codes are not to be re- AVUM level quisitioned/requested individually. MF-Made at DS/ They must be made from bulk material AVIM level which is identified by the P/N MH-Made at GS in the DESCRIPTION AND USABLE Level ON CODE (UOC) column and listed in ML-Made at SRA the bulk material group of the RPSTL. If the item is authorized to you by the 3^rd MD-Made at depot position 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 Items with these codes are not to be re- Unit/AVUM level quested/requisitioned individually.  The AF-Assembled by parts that make up the assembled item DS/AVIM level must be requisitioned or fabricated and AH-Assembled by assembled at the level of maintenance GS/level indicated by the source code.  If the AL-Assembled by 3^rd position of the SMR code authorizes SRA you to replace the item, but the source AD-Assembled by code indicates the item is assembled at Depot 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 NOTE below.)       XB If an item is not available from salvage, order it using the   CAGEC and P/N.