| ofm | OmniForm Form Data |
| ofm | TopLevel OfficeForms Blank Form |
| ofn | Microsoft Office FileNew File |
| ofp | Origin Function Plot Theme Data |
| ofr | Microsoft SMS Offer Description Data |
| ofr | Microsoft SMS Offer File |
| ofsi | Oxygen Forensic Detective UICC Image |
| ofv | DOpus Saved Favorites |
| ofw | TopLevel OfficeForms Form |
| ogc | Impulse Organica Model Data |
| ogex | Open Game Engine Exchange Data |
| ogf | OnkoS Graphics Data |
| ogg | Origin Graphs Data |
| oggu | Origin Unicode Graphs Data |
| ogi | OpenPBX Gateway Interface Data |
| ogl | Molden OpenGL Model |
| ogm | Origin Matrix Data |
| ogmu | Origin Unicode Matrix Data |
| ogo | Origin Graphic Object |
| ogrp | OFML Group Data |
| ogs | Origin LabTalk Script File |
| ogs | Origons Movie Data |
| ogw | Origin Worksheet Data |
| ogwu | Origin Unicode Worksheet Data |
| oh | DrillAssistant List Data |
| oh4 | Overhoor List Data |
| oha | Ohanae Encrypted Data for Sharing |
| ohanae | Ohanae Encrypted Data for Privat Use |
| ohs | Bink Outbound History Data |
| ohsd | HealthFrame OpenHealth Service Plug-in |
