English abbreviations from ohu to oilrig
- OHU(OHio University (non-standard, usually OU))
- OHW(Old Home Week)
- OHWS(Offensive Hand Weapon System)
- OI(Oxygen Index)
- OI&A(Office of Intelligence and Analysis (DHS))
- OIBUA(Operations In Built-Up Areas)
- OIC(Officer In Charge)
- OICC(Officer In Charge of Construction)
- OICD(Optometric Institute and Clinic of Detroit)
- OICU(Oklahoma Independent Colleges and Universities)
- OICW(Objective Individual Combat Weapon)
- OID(Object Identifier)
- OIDMTC(Ontario Interactive Digital Media Tax Credit)
- OIE(World Organisation for Animal Health (originally the Office international des épizooties, French for "International Epizootic Office"))
- OIF(Operation Iraqi Freedom)
- OIG(Office of Inspector General)
- OIH(Ohio Industries for the Handicapped)
- OII(Oxford Internet Institute)
- OIIT(Office of Informational and Instructional Technology)
- OIK(Organisation für Internationale Kontakte / Organization for International Contacts)
- OIL(Ontology Interchange Language)
- OILRIG(Oxidation Is Losing, Reduction Is Gaining)