With regard to braking systems the scope of this Directive should relate in the main to vehicles which have been granted component type-approval in accordance with Council Directive 71/320/EEC of 26 July 1971 on the approximation of the laws of the Member States relating to the braking devices of certain categories of motor vehicles and their trailers ( 5 ) although it is recognised that certain types of vehicle have been granted such approval in accordance with national standards which may differ from the requirements of that Directive.