- Do not requisition an "XA" -coded item. Order its next higher assembly. (Also, refer to the NOTE below.)
- If an "XB" item is not available from salvage, order it using the FSCM and part number given.
XC - Installation drawing, diagram, instruction sheet, field service drawing, that is identified by manufacturer's part number.
XD - Item is not stocked. Order an "XD" -coded item through normal supply channels using the FSCM and part number given, if no NSN is available.
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".
(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 indicate authorization to one of the following levels of maintenance:
C - Crew or operator maintenance done within unit or aviation unit maintenance.
O - Unit or aviation unit level can remove, replace, and use the item.
F - Intermediate direct support or aviation intermediate level can remove, replace, and use the item.
H - Intermediate 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 fourth position tells you 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).
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.