Trucks in South Asia are painted with “elaborate floral patterns and calligraphy,” Wikipedia notes. In India, common motifs include eagles, kites, a cow nuzzling a calf and the nazar battu. Decorating a truck can cost thousands of dollars.
In 2015 the Maharashtra transport department banned the words Horn OK Please on the backs of commercial vehicles. Millennium Post quoted the reasoning: “It encourages people to honk every time you pass a truck or tempo.”