ADOPTED_FROM:ENV 12694:1997 This standard refers to variable external signs (mechanical signs without electronic control excluded), when installed in public transport vehicles such as: buses, trams, trolley-buses (undergrounds and railway vehicles are excluded), and specifies location, dimensions, display characteristics, contents of information and wiring. At the present time there exists a set of technologies for such signs (ex: dot matrix, flaps, films, LCD, etc.)