| Abbreviation | Definition |
|---|---|
| BOCT | Baltimore and Ohio Chicago Terminal Railroad Company |
| BOCU | Linde LLC |
| BOCX | BOC Gases |
| BOCY | Boat Company |
| BOGU | BSL Transport |
| BOHU | Boh Environmental |
| BOMX | Baltimore and Ohio Railroad Museum |
| BONU | Bond International |
| BONU | Bond International Limited |
| BOP | Border Pacific Railroad |
| BOP | Border Pacific Railroad Company |
| BOR | Brockville & Ottawa Railway |
| BORG | Big Omaha Rail Group |
| BORX | U.S. Borax Incorporated |
| BORX | US Borax |
| BORZ | Ecorail |
| BORZ | Ecorail Incorporated |
| BOSU | W. BOS Vloeistof Transport |
| BOSU | W. BOS Vloeistof Transport, B. V. |
| BOX | Boxcar |