Why must a driver taking a loaded container to a port check documents and marks before sailing cut-off?

1. Because IMDG may require extra information (for example a container/vehicle packing certificate) and sea placards that road orange plates alone do not replace
2. Because ships ban all Class 9, so the driver should remove labels
3. Because UN numbers change when the trailer boards a ferry
4. Because IAAA forbids any ferry use of ADR vehicles