| Abbreviation | Definition |
|---|---|
| JJR | Jef Janssen Racing |
| JKM | Jan Knippenberg Memorial race |
| JRA | Japan Racing Assiociation |
| JRA | Japan Racing Association |
| JRA | Japan Racing Association's |
| JRE | Jannetty Racing Enterprise |
| JRM | Jawa Racing Motorcycles |
| KBR | Kick Back Racing |
| KBRC | Kalgoorlie Boulder Racing Club |
| KDR | Kentuckiana Drag Racers |
| KDRA | Kentuckiana Drag Racers Association |
| KG | Kristine Grace |
| KGB | Knowledge, Grace, and Beauty |
| KKR | Kasey Kahne Racing |
| KPR | King Power Racing |
| KPT | Kuhio Park Terrace |
| KRA | Korea Racing Authority |
| KRC | Kluhsman Racing Components |
| KRD | Kart Racing Development |
| KRE | Kauffman Racing Equipment |