Horn Ok Please is a common phrase that can be found behind trucks and other vehicles used in transport of heavy good very easily. The origin of this phrase is not known till date but there are various theories that exist regarding this. None of these theories are proved till date and the origin of this phrase still remains a mystery. The most common notion is that of traffic regulations in which a vehicle would honk if they need to overtake the truck. The truck driver would comply and say ok. Then the truck driver would indicate to the overtaking vehicle driver that they can pass by signaling please.