TM5-3895-346-24P Code Application/Explanation PA PB PC** PD PE PF PG Stocked items; use the applicable NSN to requisition items with these source codes.  They are authorized to the category indicated by the code entered in the 3d position of the SMR code. ** 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  3d  position  of  the  SMR  code.    The  complete  kit must be requisitioned and applied. MO-(Made at UM/AVUM Level) MF-(Made at DS/AVUM Level) MH-(Made at GS Level) ML-(Make at Specialized Repair Activ- ity (SRA)) MD-(Made at Depot) Items  with  these  codes  are  not  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 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 item from the higher level of maintenance. AO-(Assembled by UM/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  3d 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 following.) XB - If an “XB”  item is not available from salvage,  order it using the CAGE and part number given. XC - Installation drawing,  diagram,  instruction sheet,  field service drawing,  that is identified by the manufac- turer’s part number. XD - Item is not stocked.  Order an “XD”-coded item through normal supply channels using the CAGE and part number given,  if no NSN is available. 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 air- craft support items restricted by requirements of AR 700-42. (2)  Maintenance Code.  Maintenance codes tell you the level(s) of maintenance authorized to USE and REPAIR support items.  The maintenance codes are entered in the third and fourth positions of the SMR code as follows: (a)  The  maintenance  code  entered  in  the  third  position  tells  you  the  lowest  maintenance  level authorized to remove,  replace,  and use an item.  The maintenance code entered in the third position will indi- cate authorization to one of the following levels of maintenance. Code Application/Explanation C - Crew or operator maintenance done within unit maintenance or aviation unit maintenance. O - Unit maintenance or aviation unit category can remove,  replace,  and use the item. F - Direct support or aviation intermediate level can remove,  replace,  and use the item. H - General support level can remove,  replace,  and use the item. L - Specialized repair activity can remove,  replace,  and use the item. D - Depot level can remove,  replace,  and use the item. (b)  The maintenance code entered in the GS Category)  authorizes  you  to  replace  the  fourth  posi- tion tells whether or not the item is to be repaired and identifies the lowest maintenance level with the capability to do complete repair (i.e.,  perform all authorized repair functions).  (NOTE: Some limited repair may be done on  the  item  at  a  lower  level  of  maintenance,    if  authorized  by  the  Maintenance  Allocation  Chart  (MAC)  and SMR codes.) This position will contain one of the following maintenance codes: Code Application/Explanation O- Unit maintenance or aviation unit is the lowest level that can do complete repair of the item. F- Direct support or aviation intermediate is the lowest level than can do complete repair of the item. 2