recently, an mmda officer apprehended my cousin while driving his L300 FB. the reason is that his van don't have "not for hire" and "capacity" markings. he thought the officer was kidding and asked the officer to look at the plate (green). he argued that his van is a private vehicle and why should he put these markings?

if the plate is green, its private and therefore it's understood that its not for hire. is there a law concerning this or what?