The NSN system is explained in detail at this site. The country codes are given in the the following table
| NCB | National Codification Bureau (NCB) |
| 00 | USA |
| 01 | USA |
| 11 | NATO Maintenance & Supply Agency |
| 12 | Germany |
| 13 | Belgium |
| 14 | France |
| 15 | Italy |
| 16 | Czech Republic |
| 17 | Netherlands |
| 19 | Brazil |
| 20 | Canada |
| 21 | Canada |
| 22 | Denmark |
| 23 | Greece |
| 24 | Iceland |
| 25 | Norway |
| 26 | Portugal |
| 27 | Turkey |
| 28 | Luxembourg |
| 32 | Singapore |
| 33 | Spain |
| 34 | Malaysia |
| 35 | Thailand |
| 37 | South korea |
| 43 | Poland |
| 51 | Hungary |
| 66 | Australia |
| 98 | New Zealand |
| 99 | United Kingdom |