| Abbreviation | Designation | |
|---|---|---|
| ARP | Arriva RP (Polish) | railway company |
| AR | Halbspeisewagen (1. Klasse) (German) | classification |
| CH-AR | Appenzell Ausserrhoden, Kanton Appenzell Ausserrhoden (German) Appenzell Outer Rhodes, Canton of Appenzell Outer Rhodes | country code |
| Ar | Arelid (Swedish) | station code |
| Ar | Arvika (Swedish) | station code |
| 312 / AR | Rendsburg (German) | station code |