| Abbreviation | Designation | |
|---|---|---|
| M | Main (German) Main River | |
| m | million | |
| m | Fernverkehrswagen (mm: modernisiert) (German) | classification |
| MT | Malta, Repubblika ta’ Malta (Maltese) Republic of Malta | country code |
| SE-M | Skåne, Skåne län (Swedish) | country code |
| M | Międzynarodowy pospieszny (Polish) | train category |
| M | München Hbf, Landeshauptstadt München (German) Munich | fare point / vehicle registration plate |
| M | Malmö (Swedish) | station code |
| M | Malmö C, Malmö central (Swedish) | station code |
| M | Meridian (German) | offer / trademark |
| M | RB München, Regionalbereich München (German) RB Munich | railway administration |
| SE-M | Malmöhus, Malmöhus län (Swedish) | country code |
| M | Magnetbahn (BVG) (German) | train category |
| 20 / M | BD München (1953–1993), Bundesbahndirektion München (German) BD Munich | railway administration |