National Stock Number (NSN)
A 13-digit numeric code, identifying all the 'standardized material items of supply' as they have been recognized by the United States Department of Defense. P ursuant to the NATO Standardization Agreements (STANAGs), the NSN has come to be used in all treaty countries, where it is also known as a NATO Stock Number. Many countries that use the NSN program are not me mbers of NATO i.e . Japan, Australia and New Zealand. A two-digit Material Management Aggregation Code (MMAC) suffix may also be appended, to denote asset end use but it is not considered part of the NSN. An item having an NSN is said to be 'stock-listed'.