| Abbreviation | Definition |
|---|---|
| LMR | Lykens Market Racing |
| LMS | LeMans Series |
| LNR | Loppet Nordic Racing |
| LNTA | Leave No Trace Amelia |
| LOOR | Lake Ontario Offshore Racing |
| LOR | League Of racing |
| LORC | Lake Ontario Racing Council (yacht club organization) |
| LOTR | Loving Otherworldly Themed Races |
| LPRC | Lake Pontchartrain Racing Circuit |
| LR | League Racers |
| LRB | Lyndall Racing Brakes |
| LRS | Long Racetrack Shell |
| LSR | Laguna Seca Racetrack |
| LSR | lone star racing |
| LSR | Loud Street Racing |
| LWR | Light Weight Racing |
| LYRA | Lake Yacht Racing Assn |
| LYRA | Lake Yacht Racing Association |
| MAI | Mycobacterium avium intracellulare |
| MAIC | Mycobacterium Avium Intracellulare Complex |