When do you register a vehicle as a port vehicle and how does this differ from a standard vehicle registration?

If this vehicle has a mass and/or axle loads that deviate from Article 32bis of the Technical Regulations (RD 15 March 1968) and makes this movement within the port area under its own power via the public road, it is obligatory to bring this vehicle under the application of the port traffic regulations and to have it recognised as a port vehicle.