New old stock (abbreviated NOS) refers to merchandise being offered for sale which was manufactured long ago but that has never been used. Such merchandise may not be produced anymore, and the new old stock may represent the only market source of a particular item at the present time. Although not an officially recognized accounting term, it is in common use in the auction and retail industries. ebay uses the term as an http://business.listings.ebay.com/Parts_NOS-New-Old-Stock_W0QQsacatZ63960QQsocmdZListingItemList official category on their auction website.