| On Campus Session | Academic & Science |
| Office of Career Services | Academic & Science |
| Office of the Chief Scientist | Academic & Science |
| Only Child Syndrome | Academic & Science |
| Ocean Climate Stations | Academic & Science |
| Oregon Climate Service | Academic & Science |
| Office of Career Strategy | Business |
| Orthopedic Certified Specialist | Business |
| Occupancy Control System | Business |
| Overseas Courier Service | Business |
| OCP Credit Strategy Fund | Business |
| Overnight Courier Service | Business |
| One Complete Solution | Business |
| OmniAir Certification Services | Business |
| Online Conference Service | Community |
| Onondaga Central School | Community |
| Onslow County Schools | Community |
| Owl Correspondence School | Community |
| Oconee County Schools | Community |
| Officer Candidates School | Community |
| Ouachita Christian Schools | Community |
| Onondaga Central Schools | Community |
| Oklahoma Christian School | Community |
| Only Christ Saves | Community |
| Oakland Christian School | Community |
| Officers' Candidate School | Community |
| Ouachita Christian School | Community |
| Officer Cadet School | Community |
| Omaha Catholic Schools | Community |
| Optimum Computer Solutions | Computing |
| Object Compatibility Standard | Computing |
| Online Community System | Computing |
| Online Customer Support | Computing |
| One Click Search | Computing |
| Online Content Syndication | Computing |
| Oracle Content Services | Computing |
| Online Command Server | Computing |
| Open Computer and Software | Computing |
| Original Chip Set | Computing |
| Online Customer Service | Computing |
| Onboard Computer System | Computing |
| Oracle Collaborative Support | Computing |
| Oracle Consulting Services | Computing |
| Oracle Corporate System | Computing |
| One Click Services | Computing |
| Oracle Collaboration Suite | Computing |
| Open Conference System | Computing |
| Open Controls System | Computing |
| Optimizing Control System | Computing |
| On Chip Sequencer | Computing |
| Open Content Syndication | Computing |
| OEM Computing Solution | Computing |
| Office of Cyber Security | Computing |
| Output Control Software | Computing |
| Omni Computer Services | Computing |
| Oval Contact System | Contact |
| Outer Continental Shelf | Earth Science |
| Open Control System | Electronics |
| Optical Convergence Switch | Electronics |
| overseas Chinese Scholars | General |
| One Config Simple | General |
| Occupation Control System | General |
| Obsessive Compulsive Spectrum | General |
| Our Children s | General |
| Online Comment System | General |
| On Course Side | General |
| Online Class S**ks | General |
| Office of Central Services | General |
| Oral Contraceptive Steroid | General |
| Open C*nt Shot | General |
| Occupant Classification System | General |
| Overdrive Cancel Switch | General |
| Online Certification System | General |
| Oil Control System | General |
| Oil Change Schedule | General |
| Occupancy Seat Sensor | General |
| Oldsmobile Cutlass Supreme | General |
| Occupant Classification Sensor | General |
| Oxidizing Catalytic Converter System | General |
| Opel Club Sweden | General |
| Overall Operating Control System | General |
| Oldtimer Club Saurer | General |
| Oldtimer Club Salz | General |
| Orphan Car Show | General |
| Outlander Club Singapore | General |
| Online Car Show | General |
| Oil Change Service | General |
| Oil Change Sticker | General |
| Ontario Construction Secretariat | General |
| Organ Care System | General |
| Openshift Container Storage | General |
| Obsessive Compulsive Scale | General |
| of the Chief Scientist | General |
| Oracle Calendar Suite | General |
| Office of Child Support | General |
| Olori Construction Services | General |
| Office of Coast Survey | General |
| Orinoka Crash | General |
| Overseas Communication Service | General |
| Office Coffee Service | General |
| Officer Candidate | General |
| Office of Children's Services | General |
| Organic Content Standard | General |
| Office Communications Server | General |
| Operational Combat Series | General |
| Occupational Course of Study | General |
| One Corporate System | General |
| Open Collaboration Services | General |
| Online Course Selection | General |
| Optimized Cross Section | General |
| Operational Contract Support | Governmental |
| Ontario Crime Syndicate | Governmental |
| Office of Council Services | Governmental |
| Officer Commanding Police Station | Governmental |
| Office of the Chief of Staff | Governmental |
| Office of Community Services | Governmental |
| Operation Clean Sweep | Governmental |
| Orthopaedic Certified Specialist | Jobs |
| Oxford Conception Study | Medical |
| Orthopedic Clinical Specialist | Medical |
| Office of Cancer Survivorship | Medical |
| Other Cool Stuff | Messaging |
| Officer Candidate School | Military and Defence |
| On-chip Spectroscopy | Physics Related |
| Optical Calibration Sphere | Physics Related |
| Operator Communications Software | Softwares |
| Onboard Checkout System | Space Science |
| Optical Control System | Space Science |
| Opposition Caught Stealing | Sports |
| On The Course Side | Sports |
| Overnight Comparison System | Stock Exchange |
| Office Communication System | Telecommunication |
| On-line Charging System | Telecommunication |
