DFP number plates

does anybody know the implications of DFP number plates. We are in the process of registering our private car in Tanzania, and have been proposed DFP number plates. However we believe they are only for project cars, and might restrict us (eg. traveling internationally  or reexporting the car at the end of our stay)
Also the process seems very complicated, we have already spent alsmost 3 months following the TRA porocedure.
thanks for any idea and hints