| Abbreviation | Definition |
|---|---|
| JJJX | JJ Railcar Leasing |
| JJRD | J and J Railroad |
| JJRD | J and J Railroad Incorporated |
| JKBX | John Kenneth Burbridge |
| JKL | J. K. Line Incorporated |
| JKL | J.K. Line |
| JKTU | Icor International |
| JKWI | Johnsonburg, Kane, Warren and Irvine Railroad |
| JLAU | Japan Line |
| JLAU | Japan Line Limited |
| JLDU | Japan Line |
| JLDU | Japan Line Limited |
| JLEU | Japan Line |
| JLEU | Japan Line Limited |
| JLEZ | Japan Line |
| JLEZ | Japan Line Limited |
| JLHU | Japan Line |
| JLHU | Japan Line Limited |
| JLLU | Japan Line |
| JLLU | Japan Line Limited |