| Abbreviation | Definition |
|---|---|
| MFT | Style file (MetaFont source formatter) |
| MG | Generic module source (Modula-3) |
| MGF | Materials and Geometry Format |
| MGF | Micrografx Font |
| MGF | Monarch Graphics File |
| MGR | MGR bitmap file Bitmap graphics |
| MGX | Designer 4.1 Drawing |
| MHT | Message HTML document |
| MHTML | Message HTML document |
| MI | Miscellaneous |
| MIB | SNMP MIB file |
| MIC | Microsoft Image Composer Data |
| MID | Men In Drag |
| MID | Music (Musical Instrument Digital Interface) |
| MIDI | Music (Musical Instrument Digital Interface) |
| MIF | FrameMaker Data file |
| MIFF | Bitmap graphics (Magick Image File Format) |
| MII | MicroStat II Datafile |
| MIL | Raster graphics (CALS Group IV Type 2) |
| MIME | Message in MIME format ( RFC822) |