All nanny vans in service today are required by the government to have both the Chinese text "學校私家小巴" and the English text "SCHOOL PRIVATE LIGHT BUS" in capital letters painted on the sides of the vans.
During the 1980s, when living standards in Hong Kong were rising, some drivers wanted to earn extra income with their vans.
In the early 1990s, there was an accident in North Point involving a nanny van and its passengers were injured.
The accident exposed the illegal service and the government issued a ban and required all nanny vans to run only along designated routes.
School private light buses are one of three legal classified vehicles for transport of schoolchildren.