| rmc | RMCalc Data |
| rmd | IMail Server Message Data |
| rmd | RedCine-X Metadata |
| rmdb | ReefMaster Workspace |
| rmdu | RemoteMaster Device Upgrade |
| rmed | Salome-Meca Exported MED Results Data |
| rmf | Adobe Acrobat Rights Management File |
| rmf | FITS Redistribution Matrix Data |
| rmg | RootsMagic v1 Database |
| rmgb | RootsMagic v4 Database Backup |
| rmgc | RootsMagic v4 Database |
| rmir | RemoteMaster IR Setup |
| rmk | Remark Office OMR Remark Data |
| rms | Dynamite VSP Road Marking Object Style Data |
| rmscr | Rename Master Script |
| rmsendto | Rename Master Send To Data |
| rmskin | Rainmeter Skin |
| rmt | Netgear Router Firmware |
| rmtl | Rhino 3D Material Data |
| rmw | RAM Commander Database |
| rmx | Remark Office OMR Remark Data |
| rmz | Microsoft Outlook Exported Rules Data |
| rnan | Nitro Animation Resource |
| rnd | General Random Seed File |
| rnd | PGP Random Seed Data |
| rnh | SPANS Raster Header Data |
| rnk | GOLD Rank Data |
| rnk | GSEA Ranked List File |
| rnl | SPANS Raster Interchange Data |
| rno | PDP-10 Runoff Input Data |
