| Subject | English | Polish |
| construct. | open construction system | system budowlany otwarty |
| construct. | open heat-supply system | układ zasialania ciepłem otwarty |
| construct. | open steam-heating system | system ogrzewania parowego z przepompowaniem skroplin |
| phys. | open system | układ otwarty |
| construct. | open system of typification | system typizacji otwarty |
| telecom. | open systems interconnection reference model | połączenia wzajemne systemów otwartych model odniesienia |
| comp., MS | Open Systems Interconnection model | Open Systems Interconnection (A networking model introduced by the International Organization for Standardization (ISO) to promote multi-vendor interoperability. OSI is a seven-layered conceptual model consisting of the application, presentation, session, transport, network, data-link, and physical layers) |
| commun., comp. | open systems interconnection reference model | model odniesienia OSI |
| vent. | open-type exhausting system | wyciąg typu otwartego |
| vent. | open-type exhausting system | odprowadzenie otwarte |