Runway Visual Range 4 : The range over which the pilot of an aircraft on the centre line of a runway can see the runway surface markings, or the lights delineating the runway or identifying its centreline
Ministry of Business, Innovation and Employment, Glossary of terms and acronyms, Wellington, New Zealand 2010. http://wwwsosh.govt.nz/resources/glossary-u.shtml, (Occupn Hlth and Sfty - Brit) {530}