architecture acronyms and abbreviations > O

O: Oxygen 
O-O: outside to outside 
O/C: on centre 
O/S: out of service 
O/ST: off street 
O/STY: old style 
OA: Office Automation 
OA: Outside air 
OA: Overall 
OASIS: Organization for the Advancement of Structured Information Systems 
OAW: oxy-acetylene welding 
OB: oblique branch 
ob: obscure 
oBIX: Open Building Information Exchange 
OBS: Obscure 
OBS: Organizational Breakdown Structure 
OBW: observation window 
OC: on center 
OC: Operating Characteristic 
OCB: Oil Circuit Breaker 
OCR: Optical Character Recognition 
OD: open drain 
OD: outside diameter 
ODA: Open Document Architecture 
ODBC: Open Database Connectivity 
ODIF: Office Document Interchange Format 
ODL: Object Definition Language 
ODMA: Open Document Management API 
ODP: Ozone Depletion Potential 
OE: Open End 
OECD: Organization for Economic Cooperation and Development 
OEM: Original Equipment Manufacturer 
of: outside face 
OFC: off-form concrete 
OFF: Office 
OG: obscure glass 
OG: ordinary glazing 
OGIS: Open Geodata Interoperability Specification 
OH: Overhead 
OH&S: Occupational Health and Safety