| rom | Atari Jaguar ROM Image |
| rom | General ROM Image |
| rom | NES ROM Image |
| roo | Oracle CODASYL DBMS Database Root |
| root | HippoDraw ROOT Ntuples |
| rop | Actuate e.Report Parameter Template |
| rop | PSS/E OPF Model |
| ror | Resources of a Resource File |
| ros | Actuate e.Report Designer Search Definition Data |
| ros | Dynamite VSP Rail Object Style Data |
| ros | Lotus Notes Full Text Index Data |
| rot | Rotater 3D Data |
| rot | STK Central Body Rotation File |
| rou | EnRoute v3 Toolpath Data |
| rou | Route 66 Route Data |
| rov | Actuate e.Report Designer Report Object Value Data |
| rov | Siebel Report Object Variable |
| rox | Siebel Report Object Executable |
| roz | aSc Timetables Data |
| rp2 | RetroPlatform Player Archive |
| rp9-snapshot | RetroPlatform Snapshot Image |
| rpa | iTWO Project Archive |
| rpb | Radmin Phonebook |
| rpc | 3WayPack RPC Data |
| rpc | Act! Report |
| rpc | BillQuick Enterprise Invoice Data |
| rpc | Crystal Reports RPC File |
| rpc | WaterGEMS Hydraulic Analysis Report |
| rpc3 | NI Diadem RPC3 File |
| rpcp | Reason Resource Data |
