TM  10-8110-201-14&P APPENDIX C REPAIR  PARTS  AND  SPECIAL  TOOLS  LISTS Section I. INTRODUCTION C-1. Scope. a. This  Appendix  lists  repair  parts,  special tools,  test  and  support  equipment  required  for  the performance of maintenance of the drums. b. Repair  parts  listed  represents  those  authoriz- ed for use at the organizational, direct support and general support maintenance levels and will be re- quisitioned   on   an   “as   required”   basis   until stockage is justified by demand in accordance with AR 710-2. C-2. General. This  Repair  Parts  and  Special  Tools  List  is divided  into  the  following  sections: a. Repair Parts List - Section II. A list of spares and repair parts authorized for use in the per- formance  of  maintenance.  The  list  also  includes parts which must be removed for replacement of the authorized parts. Parts lists are composed of assembly  groups  in  ascending  numerical  sequence, with the parts in each group listed in figure and item  number  sequence. b. Special Tools List - Section III.  (Not  Ap- plicable). c. National Stock Number and Part Number In- dex - Section IV. A list, in ascending numerical sequence, of all National Stock Numbers appear- ing in the listings, followed by a list, in alpha- numeric sequence, of all part numbers appearing in  the  listings.  National  Stock  Number  and  part numbers are cross-referenced to each illustration figure  and  item  number  appearance. C-3. Explanation of Columns. The following provides an explanation of col- umns found in the tabular listings: a. Illustration. This column is foIlows: (1) Figure Number. Indicates number of the illustration in which shown. divided   as the  figure the item is (2) Item Number.  The number used to identify each  item  called  out  in  the  illustration. b. Source, Maintenanc, and Recoverability Codes  (SMR). (1) Source Code. Source codes are assigned to support  items  to  indicate  the  manner  of  acquiring support  items  for  maintenance,  repair,  or  overhaul of  end  items.  Source  codes  are  entered  in  the  first and second positions of the Uniform SMR code for- mat  as  follows: Code PA PB PC PD PE PF PG Definition Item  procured  and  stocked  for  anti- cipated  or  known  usage. Item  procured  and  stocked  for  insurance purpose because essentiality dictates that a minimum quantity be available in the  supply  systems. Item procured and stocked and which otherwise  would  be  coded  PA  except that  it  is  deteriorative  in  nature. Support   item,   excluding   support equipment, procured for initial issue or outfitting and stocked only for subse- quent  or  additional  issues  or  outfittings. Not  subject  to  automatic  replenishment. Support   equipment   procured   and stocked for initial issue or outfitting to specified  maintenance  repair  activities. Support equipment which will not be stocked but which will be centrally pro- cured  on  demand. Item procured and stocked to provide for sustained support for the life of the equipment.  It  is  applied  to  an  item peculiar   to   the   equipment   which, because of probable discontinuance or shutdown  of  production  facilities,  would prove uneconomical to reproduce at a later  time. C-1