'Opening' is the maximum unobstructed aperture between the upper edge or the leading edge, depending on the closing direction, of a power-operated window or partition or roof panel and the vehicle structure which forms the boundary of the window, partition or roof panel, when viewed from the interior of the vehicle or, in the case of partition system, from the rear part of the passenger compartment.
'Odprtina' pomeni največjo nezakrito odprtino med zgornjim robom ali prednjim robom (glede na smer zapiranja) stekla, pregrade ali pomične strehe na električni pogon in konstrukcijo vozila, ki omejuje steklo, pregrado ali pomično streho, če se gleda iz notranjosti vozila oziroma iz zadnjega dela potniškega prostora pri pregradah.