| NOBH | | Mobile Homes | 72205 |
| NOC | | Search, Detection, Navigation, Guidance, Aeronautical Sys | 1133421 |
| NODK | | Fire, Marine & Casualty Insurance | 1681206 |
| NOEM | | Blank Checks | 1956648 |
| NOG | | Crude Petroleum & Natural Gas | 1104485 |
| NOK | | Radio & Tv Broadcasting & Communications Equipment | 924613 |
| NOM | | - | 899782 |
| NOMA | | Services-Amusement & Recreation Services | 1994214 |
| NOMD | | Food and Kindred Products | 1651717 |
| NORD | | Services-Management Consulting Services | 1011060 |
| NOTE | | Services-Business Services, NEC | 1823466 |
| NOTV | | Services-Commercial Physical & Biological Research | 720154 |
| NOV | | Oil & Gas Field Machinery & Equipment | 1021860 |
| NOVAQ | | Electric & Other Services Combined | 1772695 |
| NOVT | | Miscellaneous Electrical Machinery, Equipment & Supplies | 1076930 |
| NOW | | Services-Prepackaged Software | 1373715 |
| NOWG | | Services-Computer Programming, Data Processing, Etc. | 1761911 |
| NP | | Insurance Agents, Brokers & Service | 2067129 |
| NPAC | | Blank Checks | 2048948 |
| NPB | | State Commercial Banks | 1336706 |
| NPCE | | Surgical & Medical Instruments & Apparatus | 1528287 |
| NPCT | | - | 1835068 |
| NPFD | | - | 1865389 |
| NPK | | Ordnance & Accessories, (No Vehicles/Guided Missiles) | 80172 |
| NPKI | | Services-Miscellaneous Equipment Rental & Leasing | 71829 |
| NPO | | Gaskets, Packg & Sealg Devices & Rubber & Plastics Hose | 1164863 |
| NPRFF | | - | 1859022 |
| NPT | | Wholesale-Chemicals & Allied Products | 2014337 |
| NPV | | - | 897421 |
| NPWR | | Electrical Industrial Apparatus | 1845437 |
| NQP | | - | 870780 |
| NRC | | Services-Commercial Physical & Biological Research | 70487 |
| NRDE | | Motor Vehicles & Passenger Car Bodies | 1759546 |
| NRDS | | Services-Computer Processing & Data Preparation | 1625278 |
| NRDY | | Services-Educational Services | 1819404 |
| NREF | | Real Estate Investment Trusts | 1786248 |
| NRG | | Electric Services | 1013871 |
| NRGV | | Miscellaneous Electrical Machinery, Equipment & Supplies | 1828536 |
| NRHI | | Retail-Nonstore Retailers | 1680689 |
| NRIM | | Savings Institution, Federally Chartered | 1163370 |
| NRIS | | Crude Petroleum & Natural Gas | 1603793 |
| NRIX | | Pharmaceutical Preparations | 1549595 |
| NRK | | - | 1195739 |
| NRO | | - | 1261166 |
| NROM | | Retail-Eating Places | 709005 |
| NRP | | Bituminous Coal & Lignite Surface Mining | 1171486 |
| NRRSF | | - | 1778940 |
| NRSAX | | - | 1663712 |
| NRSN | | Pharmaceutical Preparations | 1875091 |
| NRT | | Oil Royalty Traders | 72633 |