| Abbreviation | Definition |
|---|---|
| ITF | Internationa Tennis Federation |
| ITF | International Tennis Federation |
| ITN | International Tennis Number |
| ITPL | International Tennis Premier League |
| ITST | International Tennis Simulation Tour |
| ITTF | International Table Tennis Federation |
| IWTA | Idaho Wheelchair Tennis Association |
| IWTA | Inner West Tennis Academy |
| IWTA | International Wheelchair Tennis Association |
| JCTA | Jefferson County Tennis Association |
| JHTA | Janette Husarova Tennis Academy |
| JMTA | John McEnroe Tennis Academy |
| JPTC | Jellicoe Park Tennis Club |
| JPTC | John Powless Tennis Center |
| JTC | Junior Tennis Coaching |
| JTCC | Junior Tennis Champions Center |
| JTL | Junior Tennis League |
| JTT | Jr Team Tennis |
| JTT | Junior Team Tennis |
| JTTA | Japan Table Tennis Association |