| nmx | NI Traktor Mix Data |
| nna | NeuralWare NeuralWorks Data |
| nnb | ANNI Neural Network Batch |
| nnd | CYMFLOW Network Data |
| nnf | Cytoscape Nested Network Format File |
| nni | ANNI Neural Network Investing |
| nnl | Network Notepad Professional License |
| nnn | Filmetrics F20 Material Data |
| nnp | ANNI Neural Network Portfolio |
| nnr | NeuralWare NeuralWorks Data |
| nns | NobleNet Sealer File |
| nnt | Eudora Addressbook Database |
| nntp | NewsWatcher NNTP Data |
| nnvs | NextNine VNC Player Session Data |
| nnw | NobleNet Web Data |
| nob | Chart Navigator Pro Navigation Objects Data |
| nod | MSC Patran Nodal Results |
| nodes | PowerFolder Nodes Data |
| nog | BLAST NOG Data |
| nom | PC-DMIS NOM File |
| nop | Nikon Optional Picture Control |
| nopd | Navicat for Oracle Data Synchronization Profile Data |
| nope | Navicat for Oracle Exported Table |
| nopem | Navicat for Oracle Export Materialized View Profile |
| nopeq | Navicat for Oracle Export Query Result Profile Data |
| nopev | Navicat for Oracle Export View Result Profile Data |
| nopi | Navicat for Oracle Import Wizard Profile Data |
| nopj | Navicat for Oracle Batch Job |
| nops | Navicat for Oracle Structure Synchronization Data |
| nopt | Navicat for Oracle Data Transfer Profile Data |
| not | Adobe InCopy User Dictionary |
| not | MakeMusic Finale Note File |
| not | Zemax Element Drawing Note |
| notx | E-Sword v9 Study Note |
| notz | FiiNote Exported Note |