| Abbreviation | Definition |
|---|---|
| UKC | Universal Karate Central |
| UKK | Universitetets KarateKlubb |
| UKL | Ultimate Karate League |
| UPK | Universal Pasha Karate School |
| USANKF | USA National Karate Do Federation |
| USK | United States Karate |
| USKA | United States Karate Academy |
| USKA | United States Karate Alliance |
| USKO | United States Karate Organization |
| UWK | United World Karate |
| WAKT | Warszawska Akademia Karate Tradycyjnego |
| WBKL | World Budo Karate League |
| WCKC | Women's Center Karate Club |
| WDKC | Winged Dragon Karate Club |
| WIKC | Wesminster Ishinryu Karate Club |
| WIKF | Wado International Karate Federation |
| WJKU | World Ju-Jitsu and Karate Union |
| WKA | Washington Karate Association |
| WKA | World Karate Association |
| WKC | World Karate Confederation |