OAS Organisation of American States
OAU Organisation of African Unity
OBC Other Backward Communities
OBU Offshore Banking Unit
ODA Official Development Assistance
ODF Open Document Format
ODS Ozone Depletion Substances
OECD Organisation of Economic Co-operation and Development
OGL Open General Licence
OIC Organisation of Islamic Countries
OIGS On India Government Service
OIL Oil India Limited
OK All Correct
OM Order of Merit
ONGC Oil and Natural Gas Commission
OPEC Organisation of Petroleum Exporting Countries
OSCE Organisation for Security and Cooperation in Europe
OSD Officer on Special Duty
OXML Open Extended Marking Language