National Codification Bureau
The National Codification Bureaus or NATO Codification Bureaux (NCB) are a NATO organization that oversees the management of the NATO Codification System (NCS). It is governed by NATO Allied Committee 135 (AC/135), with each member nation's National Codification Bureau controlling and issuing its own unique NATO Stock Numberss.
Source: Wikipedia — National Codification Bureau (CC BY-SA 4.0)