(3)A public service vehicle when regularly used for carrying Government mail by under a contract with the Indian Posts and Telegraphs Department may exhibit in conspicuous place upon a plate or a plain surface of the motor vehicle the words "Mail" in red on white ground, each letter being not less than 15 centimeters in height and of a uniform thickness of 2 centimeters.Save as provided above, no motor vehicle shall display any sign or inscription which includes the word "Mail".
