This document is limited to specifying the requirements when applying material to the active interface between the wheel tread and the crown of the rail and includes trainborne and track side equipment. This document only covers the equipment and application of material to the active interface. This document specifies: the characteristics of top of rail equipment for wheel-rail interface, together with applicable inspection and test methods to be carried out for verification; all relevant terminology which is specific to the application of top of rail materials at the wheel-rail interface. This document applies to the mainline railway. NOTE This document can also be used for other railways, e.g. urban rail.