GP – General Purpose
HC – High Cube
CW – Cargo Worthy standard generally implies that the container has a valid CSC. In general, any container used for international transport must have a valid safety approval plate or “CSC plate”. CSC is the abbreviation for Container Safety Convention. Cargo Worthiness can be certified by a third party container surveyor pursuant to a physical inspection of the used shipping container.
WWT – Wind & Water Tight – a criterion under which containers are literally “wind and water tight”. In short, if you lock yourself inside the container, you should not see any light coming through the panels or roof. It should be noted that this criterion however makes no reference to the quality of the understructure. A WWT container should therefore not be considered safe for the transport of cargo; unless it is explicitly confirmed it meets the CSC. WWT + CSC = CW