TM 1-2835-209-23P Code Explanation MO-  (Made at Items with these codes are not to be requested/ AVUM Level) requisitioned individually.  They must be made MF-  (Made at from bulk material which is identified by the part AVIM Level) number in the DESCRIPTION AND USABLE ON ML-  (Made at Spe- CODE (UOC)column and listed in the Bulk Material cialized Repair group of the repair parts list in this RPSTL.  If the item Act (SRA)) is authorized to you by the 3rd position code of MD-  (Made at Depot) 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 Items with these codes are not to be requested/ AVUM Level) requisitioned individually.  The parts that make AF-  (Assembled by up the assembled item must be requisitioned or AVIM Level) fabricated and assembled at the level of mainte- AL-  (Assembled by nance indicated by the source code.  If the 3rd (SRA)) position code of the SMR code authorizes you to AD-  (Assembled by replace the item, but the source code indicates Depot) 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. 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 manufacturer's part number. XD-   Item is not stocked.  Order an "XD"-coded item through normal supply channels using the CAGE and part number given. 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 700-42. 3