TM 5-6115-365-15 C3 of  maintenance  at  the  direct  support,  general  support, and depot level. 1-6.  Explanation of Columns The  following  provides  an  explanation  of  columns  in  the tabular lists in Part I and Part II. a. Source, Maintenance, and Recoverability Codes (SMR). Note Common   hardware   items   known   to be  readily  available  in  Army  supply channels will be assigned Maintenance    codes    only.        Source codes,     Recoverability     codes,     and Maintenance  Allowances  will  not  be assigned to this category. (1) Source    code.        Indicates    the    selection status and source for the listed item.  Source codes used are: CODE EXPLANATION P......................Applied to repair parts which are stocked in or supplied from    DSA/GSA    or    Army    supply    system,    and authorized for use at indicated levels. M.....................Applies   to   repair   parts   which   are   not   procured   or stocked   but   are   to   be   manufactured   at   indicated maintenance levels. A .....................Applied   to   assemblies   which   are   not   procured   or stocked  as  such  but  made  up  of  two  or  more  units, each  of  which  carry  individual  stock  numbers  and descriptions and are procured and stocked and can be assembled by units at indicated maintenance levels. X .....................Applied to parts and assemblies which are not procured or  stocked,  the  mortality  of  which  is  normally  below that of the applicable end item, and the failure of which should  result  in  retirement  of  the  end  item  from  the supply system. X1 ...................Applied   to   repair   parts   which   are   not   procured   or stocked, the requirement for which will be supplied by use of the next higher assembly or component. X2 ...................Applied  to  repair  parts  which  are  not  stoc ked.    The indicated   maintenance   level   requiring   such   repair parts will attempt to obtain them through cannibalization; if not obtainable through cannibalization, such repair parts will be requisitioned with   supporting   justification   through   normal   supply channels. G.....................Applied  to  major  assemblies  that  are  procured  with PEMA  (Procurement  Equipment  Missile  Army)  funds for    initial    issue    only    to    be    used    as    exchange assemblies   at   DSU   and   GSU   maintenance   level. These assemblies will not be stocked above DSU and GSU level or returned to depot supply level. (2) Maintenance  code.    Indicates  the  lowest level of maintenance authorized to install the listed item. The maintenance level codes are: CODE EXPLANATION C.....................Operator maintenance O.....................Organizational maintenance F......................Direct support maintenance H.....................General support maintenance D.....................Depot maintenance (3) Recoverability   code.      Indicates   whether unserviceable  items  should  be  returned  for  recovery  or salvage. Items not coded are expendable. Recoverability codes are: CODE EXPLANATION R.....................Applied   to   repair   parts   and   assemblies   which   are economically  repairable  at  DSU  and  GSU  activities and normally are furnished by supply on an exchange basis. T......................Applied  to  high  dollar  value  recoverable  repair  parts which are subject to special handling and are issued on an exchange basis.  Such repair parts normally are repaired     or     overhauled     at     depot     maintenance activities. U.....................Applies to repair parts specifically selected for salvage by    reclamation    units    because    of    precious    metal content,  critical  materials,  high  dollar  value  reusable casings or castings. (4) This   column   also   lists,   below   the   SMR code,   an   index   number   for   each   item   in   ascending numerical sequence, which is used to locate items in the publication    when    the    Federal    stock    number    and/or reference number is not known. b. Federal  Stock  Number.    Indicates   the   Federal stock number for the item. c. Description.    Indicates  the  Federal  item  name and  any  additional  description  of  the  item  required.    A part  number  or  other  reference  number  is  followed  by the     applicable     five-digit     Federal     supply     code     for manufacturers  in  parentheses.    Repair  parts  quantities included  in  the  kits,  sets,  and  assemblies  are  shown  in front of the repair part name. d. Unit  of  Measure.    Indicates  the  unit  used  as  a basis for issue, e.g., ea, pr, ft, yd, etc. e. Quantity   Incorporated   in   Unit.      Indicates   the quantity of the item used in the functional group. f. Fifteen-Day Organizational Maintenance Allowances. (1) The   allowance   columns   are   divided   into subcolumns. Indicated in each sub-column 1-2