Technicians, vendors, officials, terminal staff, agents and pilots often plug laptops, tablets or removable media into ship computers (officials have even asked to print from an unknown USB). Where access is uncontrolled, as in drydock, layup or when taking over a ship, sensitive data should be removed and reinstalled afterwards, or at least critical data and configurations backed up beforehand, systems scanned for malware before use where possible and OT tested for correct function.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.