| REPORTING MARKS | COMPANY |
| ACL | Atlantic Coast Line Railroad Co. |
| APLZ | American President Intermodal Company Inc. |
| ARR | Alaska Railroad |
| ARZC | Arizona & California Railroad Company |
| ATSF | Atchison, Topeka & Santa Fe Railway Company |
| BAR | Bangor & Aroostook Railroad Company |
| BCOL | British Columbia Railway Company |
| BN | Burlington Northern Inc. |
| BO | Baltimore & Ohio Railroad Company |
| CGW | Chicago Great Western |
| CHTT | Missouri Pacific System |
| CN | Canadian National Railways |
| CNW | Chicago and North Western Transportation Company |
| CP | CP Rail |
| CR | Consolidated Rail Corp. |
| CRLE | Coe Rail Inc. |
| CSXT | CSX Transportation Inc. |
| DL&W | Delaware, Lackawanna, & Western Railroad Corp. |
| DTTX | TTX Corp. |
| EL | Erie Lackawanna Railroad Company |
| EPIX | Epic |
| FEC | Florida East Coast Railway Company |
| GBRX | Greenbrier Leasing Corp. |
| GN | Great Northern Railway Company |
| GNAX | Holnam, Inc |
| GTTX | TTX Corp. |
| GTW | Grand Trunk Western Railroad Company |
| KCS | Kansas City Southern Railway Company |
| KTTX | TTX Corp. |
| KWTX | K & W Trucking Company Inc. |
| L&N | Louisville & Nashville Railroad Company |
| LTTX | TTX Corp. |
| MAEX | Maersk Inc. |
| MCER | Massachusetts Central |
| MEC | Maine Central Railroad Company |
| MERX | Merco |
| MILW | Chicago, Milwaukee, St. Paul, & Pacific Railroad Company |
| MP | Missouri Pacific Railroad Company |
| MSTL | Minneapolis & St. Louis Railway Company |
| NP | Northern Pacific Railway Company |
| NTTX | TTX Corp. |
| NYSW | New York, Susquehanna, & Western Railway Corp. |
| PC | Penn Central |
| PLWX | Itel Rail Corp. |
| PRR | Pennsylvania Railroad |
| PSMX | Pullman Standard Manufacturing |
| RBCX | Rail-Bridge Corp. |
| RI | Chicago, Rock Island, & Pacific Railway |
| RTTX | TTX Corp. |
| SCL | Seaboard Coast Line |
| SFLC | Atchison, Topeka, & Santa Fe Railway Company |
| SO | South Orient Railroad Company Ltd. |
| SOO | Soo Line Railroad Company |
| SP | Southern Pacific Transportation Company |
| SSIX | Itel Rail Corp. |
| SSW | St. Louis Southwestern Railway Co. |
| STTX | TTX Corp. |
| TP | Texas & Pacific Railway Company |
| TTAX | TTX Corp. |
| TTCX | TTX Corp. |
| TTEX | TTX Corp. |
| TTFX | TTX Corp. |
| TTLX | TTX Corp. |
| TTOX | TTX Corp. |
| TTRX | TTX Corp. |
| TTUX | TTX Corp. |
| TTWX | TTX Corp. |
| TTX | TTX Corp. |
| UP | Union Pacific |
| UTTX | TTX Corp. |
| VTTX | TTX Corp. |
| WTTX | TTX Corp. |
| XTTX | TTX Corp. |