Do not requisition an "XA" item. Order its next higher assembly. (Also, refer to the NOTE
If an "XB" item is not available from salvage, order it using the CAGEC and part number
Installation drawing, diagram, instruction sheet, field service drawing, that is identified by
manufacturers part number.
Item is not stocked. Order an "XD" item through normal supply channels using the
CAGEC 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
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
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.
Crew or operator maintenance done within organizational maintenance.
Unit can remove, replace, and use the item.
Direct support level can remove, replace, and use the item.
General support level can remove, replace, and use the item.
Specialized repair activity can remove, replace, and use the item.
Depot level can remove, replace, and use the item.
The maintenance code entered in the fourth position indicates whether the item is to be repaired and
identifies the lowest maintenance level with the capability to perform complete repair (i.e. all authorized
maintenance functions). (NOTE: Some limited repair may be done on the item at a lower level of
maintenance, if authorized by the MAC and SMR codes.) This position will contain one of the following
Unit is the lowest level that can do complete repair of the item.
Direct support is the lowest level that can do complete repair of the item.