| Mountain Astronomical Research Section | Academic & Science |
| Media And Resource Services | Academic & Science |
| Mountain Area Research Section | Academic & Science |
| Monitoring Action Research System | Academic & Science |
| Math And Reading Scholars | Academic & Science |
| Meteorological Automatic Reporting System | Academic & Science |
| Mathematics Assessment Resource Service | Academic & Science |
| Monterey Accelerated Research System | Academic & Science |
| Monotone Advection and Reconstruction Scheme | Academic & Science |
| Matulich And Rowe Studios | Business |
| Music And Recording Superstore | Business |
| Music And Recording Superstores | Business |
| Meeting And Reservation Service | Business |
| Mobile Access and Retrieval System | Business |
| Milestones Actions Relationships Schedules | Business |
| Management And Reporting System | Business |
| Marston's | Business |
| Management Administrative And Reporting System | Business |
| Milwaukee Area Radio Stations | Business |
| Member Audio Response System | Business |
| Mortgage Assistance Relief Services | Business |
| Marketing Advertising Retail and Sales | Business |
| Management and Reporting Systems | Business Management |
| Mobile Audience Response Systems | Community |
| Modelling Animation And Rendering System | Community |
| Machine Assisted Reference Services | Community |
| Museum Astronomical Resource Society | Community |
| Middlebury Automated Registration System | Community |
| Manual Audience Response System | Community |
| Mono Analog Rack Synthesizer | Community |
| Model Agency Rating System | Community |
| Machine Learning, Automation, Robotics, and Space | Community |
| Midwest Association of Rail Shippers | Community |
| Mains Active Restoring System | Computing |
| Multicast Address Resolution Server | Computing |
| Multiple Access Radio Systems | Computing |
| Machine Addressed Reading Software | Computing |
| Multiuser Archival and Retrieval System | Computing |
| Machine Assisted Reference Section | Computing |
| Microsoft Azure Recovery Services | Computing |
| Minolta Automated Retrieval System | Computing |
| MIPS Assembly and Runtime Simulator | Computing |
| Multicast Address Resolution Service | Computing |
| Microsoft Alphanumeric Recognition System | Computing |
| Multiple Active Result Sets | Computing |
| Mars Network | Cryptocurrency |
| Marscoin | Cryptocurrency |
| Manitou Air Response System | General |
| Multivariate Adaptive Regression Splines | General |
| Mobile Augmented Reality Sytems | General |
| Military Arms Research Syndicate | General |
| Massive Amounts of Random Structures | General |
| Mathewson Automated Retrieval System | General |
| Mariners Alerting and Reporting Scheme | General |
| Magenn Air Rotor System | General |
| Multimedia Archaelogical Research System | General |
| Monitoring Analysis and Response System | General |
| Mobile Agricultural Robot Swarms | General |
| Microprogrammable Accelerator For Rapid Simulations | General |
| Mayfield And Ragni Studio | General |
| Measurable Accessible Responsive Substantial | General |
| MIPS Assembler and Runtime Simulator | General |
| Mid American Racing Series | General |
| Motor Alternator Reversible System | General |
| Moving Armature Red Signal | Governmental |
| Maintenance And Ramp Safety | Governmental |
| Mobile Automated Regulatory Services | Governmental |
| Mitigation And Response System | Governmental |
| Military Affiliated Radio Services | Governmental |
| Militians At Ready Stance | Governmental |
| Mobile Assault, Rescue, and Security | Governmental |
| Military Affiliated Radio Service | Governmental |
| Mid-Air Refueling Squadron | Governmental |
| Mini Assault Rifle System | Governmental |
| Manga Anime Review Site | Internet |
| Multivariate Additive Regression Splines | Maths |
| Molecular Adsorbent Recirculating System | Medical |
| Mutually Agreed Resignation Scheme | Medical |
| Medication Allocation Records | Medical |
| Medication Adherence Rating Scale | Medical |
| Medical Amateur Radio Society | Medical |
| Multi-Agency Referral Service | Medical |
| Making All Recreation Safe | Medical |
| Military Affiliate Radio Sys | Military and Defence |
| Military Auxiliary Radio System | Military and Defence |
| Military Affiliated Radio System | Military and Defence |
| Military Affiliate Radio System | Military and Defence |
| Mechanized Assault Recon and Strike | Military and Defence |
| Mobile Assault Rescue and Strike | Military and Defence |
| Marine Accident Reporting Scheme | Military and Defence |
| Mobile Adjustable Ramp System | Military and Defence |
| Military Armaments Research Syndicate | Military and Defence |
| Mac Address Registration System | Networking |
| Medical And Related Sciences | Regional |
| Martin Automatic Reporting System | Space Science |
| Modular Airborne Recorder System | Space Science |
| Muffin Andrew Rugby Start | Sports |
