| Abbreviation | Definition |
|---|---|
| DLW | Diesel Locomotive Works |
| DLWR | Depew Lancaster and Western Railroad Company Incorporated |
| DLWR | Depew, Lancaster and Western Railroad |
| DLWX | Delaware, Lackawanna and Western Railroad (Norfolk Southern) |
| DM | Detroit and Mackinaw Railway Company |
| DM | Lake State Railway |
| DM | Lake State Railway Company (formerly Detroit and Mackinac Railway) |
| DMCU | Sea-Can Containers |
| DME | Dakota Minnesota and Eastern Railroad Corporation |
| DME | Dakota, Minnesota and Eastern Railroad |
| DMHX | Davenport Mammoet |
| DMHX | Davenport Mammoet L.L.C. |
| DMIR | Duluth Missabe and Iron Range Railway Company |
| DMIR | Duluth, Missabe and Iron Range Railway |
| DMIX | ADM Transportation |
| DMIX | Minnesota Corn Processors Bulk Products Division |
| DMLX | Dresser Mineral (GE Railcar Services Corporation) |
| DMLZ | DML Containers |
| DMM | Dansville and Mount Morris Railroad |
| DMM | Dansville and Mount Morris Railroad Company |