Operating instructions

TM 11574A-OI
4-5
echelon.
d. SERIES P: PARTS PROCURED, SUPPLY SYSTEM STOCK
PA Applied to items procured for the Marine Corps supply system for
anticipated or known usage.
PB Applied to items for which no usage is anticipated, but procured for
the Marine Corps supply system in limited quantity for issuing purposes.
PC Applied to items procured for the Marine Corps supply system
which would be coded PA except that they are deteriorative in nature.
PG Applied to parts procured from the Marine Corps supply system to
provide for the 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.
SERIES X: NOT PROCURED, GENERALLY IMPRACTICAL FOR STOCKING,
MAINTENANCE, OR MANUFACTURE
Items listed in this publication, which are source coded XA or XB, may have been
subsequently assigned an NSN because of other application in the Marine Corps. Therefore,
if an item source coded in the XA or XB series in this publication is required, users are
directed to first make the following investigations:
Check the corresponding part number in the Master Cross-Reference List (MCRL), to
determine if an NSN has been assigned.
If an NSN has been obtained from the above check, refer to the Management Data List
(MDL) for the latest supply management decision regarding the stock number.
Check stock for availability of part(s) having a National Stock Number.
If the review of stock discloses that materiel is not available, refer to the MDL for inventory
record data regarding the preferred NSN which may have been obtained in the Master
Cross-Reference List (MCRL) and Management Data List (MDL) review.
Prepare a requisition citing the stock number shown in the Management Data list (MDL).
The above review will assist the user in obtaining the correct item of supply from the supply
system, when available, rather than through alternate methods such as obtaining the desired
part from salvage, requisitioning the next higher assembly, or recommending that the
equipment be overhauled or retired. If a stock number for the desired item does not exist,
then the source of supply as defined below will prevail:
XA Applied to items not maintained in the supply system; replacement
of these parts is neither practical nor economical. Support of the end
equipment will be affected by replacing the next higher assembly.
XB Applied to items not procured for stock, but may be acquired for
use through salvage. Activities requiring such items will attempt to obtain
them from salvage, if not obtainable from salvage, all efforts to manufacture
or assemble the item should be exhausted prior to requisitioning. Such
items will be requisitioned through normal supply channels citing
manufacturer’s code and part number with supporting justification.
XC Applied to installation drawing, diagram, instruction sheet or field
service drawing identified by a manufacturer’s part number.