| Abbreviation | Definition |
|---|---|
| DJLX | DJJ Leasing Limited |
| DJMX | Daniel John Marnell |
| DJPX | David J. Joseph Company |
| DJPX | David J. Joseph Transportation |
| DJRX | David J. Joseph Company |
| DJRX | David J. Joseph Transportation |
| DJTX | David J. Joseph Company |
| DJTX | David J. Joseph Transportation |
| DKPX | Duke Power |
| DKPX | Duke Power Company (Scale Test Cars) |
| DKS | Doniphan, Kensett and Searcy Railway (Union Pacific Railroad) |
| DKS | Union Pacific Railroad Company |
| DKUX | Exxon Company U S A |
| DKUX | Exxon Mobil Corporation |
| DL | Delaware Lackawanna |
| DL | Delaware-Lackawanna Railroad Company |
| DL | Diesel Locomotive |
| DLC | Drummond Lighterage |
| DLCR | Delaware Coast Line Railroad |
| DLCX | Dearborn Leasing Co. (Waste Management) |