| Abbreviation | Definition |
|---|---|
| NMTXZ | Novametrix Medical Systems, Inc. |
| NMUS | Net4Music (now called MakeMusic) |
| NNBR | N N Ball & Roller, Inc. |
| NNCI | NetNation Communications |
| NNCIE | NetNation Communications |
| NNDS | N D S Group, PLC. |
| NNET | Nostalgia Network |
| NNGI | Natural Nutrition Group, Inc. |
| NNSWF | Net Nanny Software International, Inc. |
| NNUP | Nocopi Technologies, Inc. |
| NOBH | Nobility Homes, Inc. |
| NOBL | Noble International, LTD. |
| NODB | North Dallas Bank & Trust Company |
| NOGAF | Noga Electro Mechanical Industries 86 |
| NOGAF | Noga Electro Mechanical Industries 86 (de-listed) |
| NOGAF | Noga Electro Mechanical Industries 86 (de-listed) |
| NOGWF | Noga Electro Mechanical Industries 86 |
| NOGWF | Noga Electro Mechanical Industries 86 (de-listed) |
| NOGWF | Noga Electro Mechanical Industries 86 (de-listed) |
| NOIZ | Micronetics Wireless, Inc. |