USABLE ON CODE. The usable on code appears in the lower left corner of the Description Column
heading. Usable on codes are shown as "UOC:.." in the Description Column (justified left) on the last line of the
applicable item description/nomenclature. Uncoded items are applicable to all models. Identification of the usable on
codes used in this RPSTL are:
FABRICATION INSTRUCTIONS. Bulk materials required to manufacture items are listed in the Bulk
Material Functional Group of this RPSTL. Part numbers for bulk materials are also referenced in the description column
of the line entry for the item to be manufactured/fabricated. Detailed fabrication instructions for items source coded to be
manufactured or fabricated are found in TM 5-4220-225-14.
INDEX NUMBERS. Items which have the word BULK in the figure column will have an index number shown
in the item number column. This index number is a cross-reference between the National Stock Number/Part Number
Index and the bulk material list in Section II.
ASSOCIATED PUBLICATIONS. The publications listed below pertain to the MK12 System and its
Operator, Unit, Direct Support and General
Support Maintenance Manual, MK12.
HOW TO LOCATE REPAIR PARTS.
When National Stock Numbers or Part Numbers are NOT Known.
First. Using the table of contents, determine the assembly 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.
Second. Find the figure covering the assembly group or subassembly group to which the item belongs.
Third. Identify the item on the figure and use the Figure and Item Number Index to find the NSN.
When National Stock Number or Part Number is Known.
First. Using the of National Stock Number and Part Number Indexes find the pertinent National Stock
Number or Part Number. The NSN index is in National Item Identification Number (NIIN) sequence (see paragraph 4.a.).
The part numbers in the Part Number index are listed in ascending alphanumeric sequence (see paragraph 4.b.). Both
indexes cross-reference you to the illustration/figure and item number of the item you are looking for.
Second. Turn to 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.
ABBREVIATIONS. Abbreviations used in this manual are listed in MIL-STD-12.