In Hong Kong, public bus, public light bus (also known as green minibus) and residential bus routes bear their own route numbers. Public buses The numbering systems of public buses can be classified into Hong Kong Island routes, Kowloon and New Territories routes, Lantau Island (New Lantao Bus) routes, MTR Bus routes, Cross harbour bus routes and Airport and North Lantau external bus routes. Their route numbering systems are independent. For example, there are both route 1, and route 2 on Hong Kong Island, Kowloon and Lantau Island respectively. In the past, the air-conditioned bus routes were numbered as 200's (Kowloon and New Territories) and 500's (Hong Kong Island). However, this identification became void after they phased out all the non-aircon buses; and since then bus routes has been playing around with the old numbers. At one time, there were two "N11" bus routes in Tung Chung, namely, Airport overnight route N11 and Lantau Island overnight route N11. The latter is no longer in service. Public light buses The numbering systems of public light bus (green minibuses) are classified into Hong Kong Island public light bus routes, Kowloon public light bus routes and New Territories public light bus routes. There is one public light bus route operating in Airport or on Lantau Island (901). Their route numbering systems are independent too. However, for cross harbour public light bus routes, the route numbers from Hong Kong Island or New Territories are used instead. Residential buses Residential bus routes are the routes which are requested to operate by the residents or estates community. At the past, the route numbers are with a suffix "R". The first residential bus route was route 88R from City One Shatin to Kowloon Tong station (it was then renumbered 62R). From c. 2003, the route numbers have been changed as prefix "HR", "KR", and "NR". They stand for Hong Kong Island residential bus routes, Kowloon residential bus routes and New Territories residential bus routes respectively. There is no residential bus services on Lantau Island (except Discovery Bay) and the Airport. Route numbering system for public buses Note that xx represents numbers. Hong Kong Island routes 2xx & 3xx: Recreational routes 5xx: Existing air-conditioned bus routes (The rule was abolished when China Motor Bus ceased operations in 1998.) 7xx: Island Eastern Corridor express routes Kowloon & NT routes xx: Existing bus routes operated by Kowloon Motor Bus, except