Several manufacturers are often involved in the construction of a motorhome. The vehicles will then be homologated in stages.
For example, the power car from FIAT with a COC (stage 1) can be assembled into a chassis with a frame-rear axle attachment from, for example, Al-Ko (COC stage 2). The body manufacturer HYMER builds a motorhome on this and issues a HYMER COC (level 3). When it comes to issues such as permissible tires or loads/loads , the COC of the last level is usually decisive.
Each homologated level has its own EC type approval number and there should also be a corresponding nameplate on the vehicle.