| Abbreviation | Definition |
|---|---|
| MSURC | Michigan State University Racing Club |
| MTRA | Monster Truck Racing Association |
| MTRC | Motor Triathlon Race Car |
| MTRL | Monster Truck Racing League |
| MVRC | Moonee Valley Racing Club |
| MWM | Mark Walter Martin |
| MWR | Michael Waltrip Racing |
| NABR | North American Bavarian Racing |
| NACRA | North American Catamaran Racing Association |
| NADRA | North American Dog Racing Association |
| NAG | National Air Racing Group |
| NARF | North American Racewalking Foundation |
| NARI | North American Racewalking Institute |
| NARRA | North American Road Racing Association |
| NART | North American Racing Team |
| NASC | North American Sarracenia Conservancy |
| NASCAR | National Assocaition for Stock Car Auto Racing |
| NASCAR | National Association for Stock Car Auto Racing |
| NASCAR | National Association of Stock Car Auto Racing |
| NASCAR | National Association Stock Car Auto Racing |