TM 10-3930-665-13&P 6.  How to Locate Repair Parts. a. When National Stock Number or Part Number is Not Known. (1) First.  Using the table of contents, determine the assembly group or subassembly group to which the item belongs.    This  is  necessary  since  figures  are  prepared  for  assembly  groups  and  subassembly  groups,  and  listings  are divided into the same groups. (2) Second.  Find the figure covering the assembly group or subassembly group to which the item belongs. (3) Third.  Identify item on the figure and note the item number. (4) Fourth.  Refer to the Repair Parts List for the figure to find the part number for the item number noted on the figure. (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.  The part numbers in the   Part   Number   Index   are   listed   in   ascending   alphanumeric   sequence.      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 are looking for, then locate the item number in the repair parts list for the figure. 7.  Abbreviations. Abbreviation Explanation NIIN Acronym  for  National  Item  Identification  Number  (consists  of  the  last  9  digits  of the NSN) RPSTL Acronym for Repair Parts and Special Tools List SMR Acronym for Source, Maintenance and Recoverability Code TMDE Acronym for Test, Measurement, and Diagnostic Equipment 8