then you can say Erankulam for Cochin and Noida for Nizamuddin . Mr Liar is right he has said this city (not suburban or main station) which does not have station . Could you give Navi Mumbai Station Code, Noida station Code. There was station in Cochin but that station is closed and no train start from there ( try why there is no train from Cochin (CHTS) after doing your google ) to improve your KB (knowledge base)