TM10-5411-201-24P TO35E4-178-4 CODE AD XA XB x c XD DEFINITION Item   to   be   assembled   at   depot   main- tenance  levels. Item  is  not  procured  or  stocked because  the  requirements  for  the item   will   result   in   the   replacement of  the  next  higher  assembly. Item  is  not  procured  or  stocked.  If not available through salvage, requisition. Installation  drawing,  diagram, instruction  sheet,  field  service drawing  that  is  identified  by manufacturers’   part   number. A   support   item   that   is   not   stocked. When   required   item   will   be   procured through  normal  supply  channels. (*)   NOTE:   For   USAF   and   the   USA   Safeguard Program  only  Code   “F”  will  be  used  to  denote intermediate    maintenance. On  joint  programs use  of  either  code  F  or  H  by  the  joining  service will   denote   intermediate   maintenance   to   USAF and  USA  Safeguard  Program. (2)   Uniform   Maintenance   Codes   applicable to  all  Military  Services:    GENERAL:    Maintenance Codes  are  assigned  to  indicate  the  levels  of  main- tenance   authorized   to   USE   and   REPAIR   support items.   The   Maintenance   Codes   are   in   the   third and   fourth   position   of   the   Uniform   SMR   Code Format. (a)   USE   (THIRD   POSITION):   The   Main- tenance  Code  entered  in  the  third  position  indicates the   lowest   level   maintenance   level   authorized   to remove,  replace,  and  use  the  support  item.  The Maintenance   Code   entered   in   the   third   position indicates   one   of   the   following   levels   of   main- tenance. Code 0 F H D G Application/Explanation Support   item   is   removed,   replaced, used   at   the   organizational   level   of maintenance. Support   item   is   removed,   replaced, used   at   the   following   intermediate levels: USAF  -  Intermediate  (*) USA  -  Direct  Support  (*) USN - Afloat USMC - Third Echelon Support  item  is  removed,  replaced,  used at  both  afloat  and  ashore  intermediate levels: Navy only. Support  item  is  removed,  replaced,  used at  the  following  intermediate  levels: USAF  -  Intermediate  (*) USA  -  General  Support  (*) USN  –  Ashore  (only) USMC  -  Fourth  Echelon Support  items  that  are  removed, replaced,  used  at  Depot  only: USAF -   Depot,   Mobile   Depot   and Specialized  Repair  Activity USA  -  Depot,  Mobile  Depot  and Specialized  Repair  Activity USN   -   Aviation   Rework,   Avoinics   and Ordinance  Facilities  and  Shipyard. USMC - Depot (b)   REPAIR   (FOURTH   POSITION): 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) 3