| Abbreviation | Definition |
|---|---|
| NSG | Data (Lotus Notes) |
| NSH | Data (Lotus Notes) |
| NSS | Norton ScreenSaver module (NC - NDW Screen Saver) |
| NST | NoiseTracker Music module |
| NSX | SuccessWare SIX 3.00 Compound index file |
| NT | Startup files (Windows NT) |
| NTF | Lotus Notes Data file |
| NTR | NetRun Executable ASCII text file |
| NTS | NetSend Executable ASCII text file |
| NTS | Norton Tutorial |
| NTX | Database index (Clipper 5) |
| NUF | Message for New Users on their First call ( Procomm Plus) |
| NWS | Latest News - Information text file - ASCII |
| NXT | Sound (NeXT format) |
| NZB | Newzbin |
| O | Object file ( Unix - Atari - GCC) |
| O | UNIX Object file |
| O$$ | Outfile (Sprint) |
| OAZ | Fax (NetFax Manager) |
| OB | Object cut/paste file (IBM LinkWay) |