Specifies design and installation dimensions of a shank-type 50 mm towball on a towbar, marking requirements for towbars used on passenger cars (including forward control passenger vehicles and off-road passenger vehicles), light goods vehicles, and light omnibuses intended for towing of caravans and trailers of up to 3.5 t aggregate trailer mass. Describes static tests for longitudinal and vertical loading in tension and compression and for transverse load, and a dynamic test.