| Abbreviation | Definition |
|---|---|
| DSDX | Pullman Leasing (GE Railcar Services) |
| DSEX | East Carbon Development |
| DSIX | Dowell Schlumberger |
| DSIX | Dowell Schlumberger Incorporated |
| DSLX | DeGussa Corporation |
| DSLZ | Intermodal Services Inc. |
| DSLZ | Intermodal Services Incorporated |
| DSRC | Dakota Southern Railway |
| DSRC | Dakota Southern Railway Company |
| DSRR | Delta Southern Railroad |
| DSRR | Delta Southern Railroad Company |
| DSRX | Downeast Scenic Railroad |
| DSSA | Duluth, South Shore & Atlantic Railway (Canadian Pacific Railway) |
| DSSX | Detroit Salt |
| DT | Decatur Junction Railway |
| DT | Decatur Junction Railway Company |
| DT&I | Detroit, Toledo, and Ironton Railroad Company |
| DTCX | DTE Transportation Services |
| DTEX | Dresser Transportation Equipment |
| DTEX | Dresser Transportation Equipment Division Dresser Industries (Test Cars) |