| NRA | National Rifle Association |
| NRA | National Rifle Association Deutschland e.V. |
| NAR | National Association of Realtors |
| NACA | National Air Charter Association |
| NBA | National Basketball Association |
| NAB | National Association of Broadcasters [USA] |
| NFPA | National Fire Protection Association |
| NAPM | National Association of Purchasing Management |
| NCSA | National Computer Security Association |
| NCSA | National Customer Service Association |
| NAGE | National Association of Government Employees Quincy, [MA], http://www.nage.org |
| NACD | National Association of Computer Dealers |
| NAIC | National Association of Insurance Commissioners Kansas City, [MO], http://www.naic.org |
| NCAA | National Collegiate Athletic Association |
| NRTA | National Retired Teachers Association |
| NEMA | National Electrical Manufacturers Association |
| NOMA | National Online Media Association |
| NCGA | National Computer Graphics Association |
| NCGA | National Computer Graphics Association |
| NMEA | National Marine Electronics Association |
| GNMA | Government National Mortgage Association |
| NABBA | National Amateur Bodybuilding Association Lahnau-Dorlar, http://www.nabba.de |
| ANNA | Association of National Numbering Agencies [engl.] |
| NASDAQ | National Association of Security Dealers Automated Quotations ein automatisches Kursnotierungssystem für Wertpapiere |
| BAR | Browning Automatic Rifle [engl.] Automatische Pistole |
| BLR | Breech Loading Rifle [engl.] Durch den Verschluss zu ladendes Gewehr |
| CN | Canadian National Eisenbahngesellschaft |
| DCA | Washington [National] DC |
| NP | National Profile |
| B.N. | Bibliotheque national [frz.] Französische Nationalbibliothek |
| NG | National Guard |
| ANC | Afrikanischer National-Kongress |
| NII | National Information Infrastructure |
| BNP | Banque national de Paris [frz.] Französische Nationalbank, Paris |
| NAS | National Academy of Sciences |
| BRU | Brussels National Airport Belgien [Internationaler Airport Code] |
| NAS | National Advanced Systems |
| ONS | Office of National Statistics |
| INA | Institut National de l'Audiovisuel Paris, http://www.ina.fr |
| NWS | National Weather Service [USA] |
| ORNL | Oak Ridge National Laboratory |
| NAS | National Audubon Society |
| Nat. Geogr. Mag. | National Geographic Magazine Zeitschrift |
| NRC | National Research Council |
| NBC | National Broadcasting Company |
| NAS | National Aircraft Standards |
| NRN | National Research Network |
| NAM | National Account Manager |
| NPL | National Physical Laboratory Teddington, http://www.npl.co.uk |
| NPR | National Public Radio |