Source:
https://scmp.com/article/120868/taxi-signs

Taxi signs

MAY I suggest that every taxi should have a 'Hong Kong' board, and a 'Kowloon' board, in addition to their 'out of service' board.

When a Hong Kong taxi driver is in Kowloon and wants to return to the island, he can display 'Hong Kong'. The reverse could be applied to Kowloon cabs. This way, people can take taxis which are headed where they want to go.

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