| M18 | Mooney Mite M-18 
| Others |
| M18 | PZL-Mielec M-18 Dromader
| Others |
| M1A | MPEG-1 audiostream
| Others |
| M1CS | Mobil 1 Cup Series
| Others |
| M1D | Microsoft One Drive
| Others |
| M1FC | Model 1 Full Capacity
| Others |
| M1RF | Mobil 1 Rally Formula
| Others |
| M1S | MPEG-1 systemstream
| Others |
| M1SCGP | Mobil 1 Sports Car Grand Prix
| Others |
| M1TG | Mobil 1 The Grid
| Others |
| M1V | MPEG-1 IPB videostream
| Others |
| M1V | Mpeg1 Video
| Others |
| M2 | ICH M2 Expert Working Group (EWG) [electronic standards for transmission of regulatory information]
| Others |
| M2 | Metalsmith 2nd Class Petty Officer
| Others |
| M2 | Modula 2 language source code file
| Others |
| m2 | second marriage
| Others |
| M2 EWG | ICH M2 Expert Working Group
| Others |
| M2 OEI | Momentum2 On Ear Headphone ipod
| Others |
| M20 | Grayson County Airport, Leitchfield, Kentucky USA
| Others |
| M2006 | Melbourne 2006 Commonwealth Games
| Others |
| M204 | Model 204 DataBase Management System
| Others |
| M204 | Model 204 Database Management System (Computer Corporation of America)
| Others |
| M21 | Muhlenberg County Airport, Greenville, Kentucky USA
| Others |
| M22 | Farallon's MacRecorder Sound format, sampling rate 22k
| Others |
| M22 | Russellville Municipal Airport, Russellville, Alabama USA
| Others |
| M23 | March 23 Movement
| Others |
| M23 | Newton Airport, Newson, Mississippi USA
| Others |
| M24 | Dean Griffin Memorial Airport, Wiggins, Mississippi USA
| Others |
| M25 | Mayfield Graves County Airport, Mayfield, Kentucky USA
| Others |
| M26 | Windsor Municipal Airport, Windsor, Missouri USA
| Others |
| M27 | Waldron Municipal Airport, Waldron, Arkansas USA
| Others |
| M28 | Mid Continent Airport, Hayti, Missouri USA
| Others |
| M29 | Hassell Field Airport, Clifton, Tennessee USA
| Others |
| M2A | MPEG-2 audio Sound
| Others |
| M2AF | Message To All Friends
| Others |
| M2C | Bmw M2 Competition
| Others |
| M2C | Market to Consumer
| Others |
| M2C | Mobile to Car
| Others |
| M2C | Music to Car
| Others |
| M2C2 | Mini Motoring Club of the Carolinas
| Others |
| M2CS | Bmw M2 Clubsport
| Others |
| M2D | Modular Mini Display
| Others |
| M2DART | Modular Mini Display for Advanced Research Training
| Others |
| M2DI | Mahindra and Mahindra Direct Injection
| Others |
| M2DICR | Mahindra and Mahindra Direct Injection Common Rail
| Others |
| M2E | Miles to Empty
| Others |
| M2E | Montana 2wd Economy
| Others |
| M2F | Mail to Fax
| Others |
| M2FM | Modified Double Frequency Modulation
| Others |
| M2G | Miles to Go
| Others |