ARMY TM 9-2815-255-24P AIR FORCE TO 38G1-95-4 MARINE CORPS TM 2815-24P/2 6. How  to  Locate  Repair  Parts.  -  Continued (5)   Fifth.   Refer   to   the   Part   Number   Index   to   find   the NSN, if  assigned. b. When  National  Stock  Number  or  Part  Number  is  Known. (1) First. Using   the   Index   of   National   Stock   Numbers and  Part  Numbers, find  the  pertinent  National  Stock  Number  or  Part Number. The   NSN   index   is   in   National   Item   Identification   Number (NIIN)  sequence  (see  4.a(1)). The  part  numbers  in  the  Part  Number index    are    listed    in    ascending    alphanumeric    sequence (see   4.b). Both   indexes   cross-reference   you   to   the illustration    figure    and item  number  of  the  item  you  are  looking  for. (2) Second. After  finding  the  figure  and  item  number, verify  that  the  item  is  the  one  you're  looking  for,  then  locate  the item  number  in  the  repair  parts  list  for  the  figure. 7. Abbreviations. (Abbreviations  must  be  applicable  to  specific RPSTL  and  not  listed  in  MIL-STD-12). Abbreviations AVIM Explanation Aviation    Intermediate Maintenance AVUM Aviation    Unit    Maintenance BOI Basis  of  Issue DS Direct    Support GS MAC General    Support Maintenance    Allocation Chart NIIN National    Item Identification    Number (consists  of  the  last g-digits  of  the  NSN) NSN RPSTL National   Stock   Number Repair   Parts   and Special   Tools   List 11