| nfb | Nokia Phone Backup |
| nfc | Nokia Phone Backup |
| nfg | Gambit Strategic Game Format File |
| nfr | CONTAM Node Flow Results Data |
| nfz | JB BAHN Vehicle Data |
| nga | ngPlant Model Archive |
| ngc | Xilinx Platform Studio Generated Netlist |
| ngd | Xilinx ISE Native Generic Database |
| nge | neXus Personal Security Client Data |
| ngf | NetSight Generated Format Data |
| ngm | Xilinx ISE Map Intermediate Data |
| ngp | NeoGeo Pocket ROM Image |
| ngp | ngPlant Model Data |
| ngrr | Guitar Rig User Presets |
| ngs | NGSSniff Data |
| ngw | NGRAIN 3D Data |
| nhcode | Mastercam NetHASP Code |
| nhd | NetHelpDesk Page Data |
| nhm | Microsoft SMS NHM Data |
| nhx | New Hampshire eXtended Format Data |
| nick | Microsoft Outlook 2000 Auto Complete Nick List |
| nicrash | NI Traktor Crash Data |
| nid | Nikon Capture IPTC Data |
| nifcache | Gamebryo NIF Cache |
| nii | NIfTI-1 Data Format File |
| nil | Norton Icon Library File |
| nin | BLAST Nucleotide Database |
| niv | theWord New International Version Module |
| nix | IBM Rational XDE Node Instance File |
| njb | Nikon Photo Index |
| njf | Lotus Notes Job Data |
| nji | Nero BackItUp Job Information |
| njob | NDARC Job Data |
| njt | Nero BackItUp Job Template |
| nk2 | Microsoft Outlook 2002 Auto Complete Nick List |