which transactions may be considered relevant for processing or correction. MAINTENANCE CODE— Two-position codes used in Source, Maintenance and Recoverability (SM&R) codes, with the first position indicating the lowest maintenance level authorized to remove, replace, and use the support item. The second position indicates the maintenance level with the capability to perform complete repair. MATCHED SET— A group of two or more separate components functioning together in a single system. These components are normally re- moved, repaired, checked, adjusted, calibrated, and installed together. MATERIAL OBLIGATION— Unfilled quantity of a requisition that is not immediately available for issue, but is recorded by the inventory manager or stock point as a commitment for future issue. MATERIAL OBLIGATION VALIDATION (MOV)— A system used to verify the unfilled quantity of a requisition that is not immediately available for issue to the requisitioner, but is recorded as a commitment against existing or prospective stock due or direct deliveries from vendors. MILITARY ORDINARY MAIL (MOM)— A special procedure approved by the U.S. Postal Service for providing air transportation of official standard mail “B” at a rate considerably cheaper than for priority mail. It may also be used for official periodicals and standard mail “4” if considered essential to timely delivery. MISSING, LOST, STOLEN, OR RECOVERED (M-L-S-R) Government Property-A program that requires the reporting of missing, lost, stolen, or recovered government material. MISSION ESSENTIAL SUBSYSTEM MATRICES (MESM)— The list of equipment system/ subsystem published in OPNAVINST 5442.4 that must be on board and in working order before an aircraft can qualify as mission ready. NATIONAL CODIFICATION BUREAU (NCB) CODE— A two-digit code included in the fifth and sixth digits of a national stock number (NSN) or a NATO stock number. In an NSN, it identifies the United States as the country that assigned the stock number. In a NATO stock number, it identifies the NATO country that assigned the stock number or indicates that the stock number is used by two or more countries. NAVAL AVIATION LOGISTICS COMMAND MANAGEMENT INFORMATION SYSTEM (NALCOMIS)— An online, interactive computer system designed to collect, store, process, and distribute data in a timely and accurate manner. NAVAL INVENTORY CONTROL POINT (NAV- ICP)— This includes the NAVICP Philadelphia (formerly ASO) and NAVICP Mechanicsburg (formerly SPCC). NAVY ITEM CONTROL NUMBER (NICN)— Items of material not included in the Federal Catalog System, but stocked or monitored in the Navy supply system. NICNs are 13-character iden- tification numbers assigned by NAVICPs or other Navy item managers for permanent or temporary control of selected non-NSN items under their cognizance. NET UNIT PRICE— Price charged for a DLR when the carcass is turned in. Net unit price includes repair cost, replacement cost when item is BCM, and a surcharge. NEXT HIGHER ASSEMBLY— Refers to the next higher assembly, on or with which, an item is used as a subassembly, part, attachment, or accessory. NODE— A DLR collection, consolidation, and trans- shipment point (does not perform validation of part number/drawing to NSN). It may be operated by a freight agent (civilian contractor) or government personnel. NON-TRANSACTION ITEM REPORTING (TIR) ACTIVITY— An activity that makes monthly or quarterly asset summary reports to the NAVICP rather than daily transaction reports. OPERATING SITE— Any activity, either afloat or ashore, authorized to stock repairable items in a retail level (consumer or intermediate) inventory. OPERATING TARGET (OPTAR)— An estimate of the money required by an operating ship, staff, AI-5