Occasionally, when a Vehicle Crossing has been installed, there is a follow up call to request a white "H" mark. The decision as to whether a "H" mark is provided is made by the Traffic & Transportation Division. "H" marks are used for properties adjacent to public buildings - e.g. schools, offices, shops - the distance from such buildings is not specific and is dependant upon other environmental factors. "H" marks are not available for residential exclusive areas.