<P> Horn OK Please is a phrase commonly painted on commercial vehicles like trucks, buses or local taxis in India . The purpose of the phrase is to alert a driver of a vehicle approaching from behind to sound their horn in case they wish to overtake . </P> <P> On April 30, 2015, the Government of Maharashtra banned the use of "Horn OK Please" on the rear side of commercial vehicles, on the grounds that it encourages motorists to honk unnecessarily and leads to noise pollution . Signage on the rear side of commercial vehicles, such as trucks and tempos, across Maharashtra is a gross violation of Section 134 (1) of the Maharashtra Motor Vehicle Rules, which deals with signage to be used on the rear and sides of vehicles . </P>

What do you mean by horn ok please