Jau Gwei
Jau Gwei (Chinese: 走鬼; Jyutping: zau2 gwai2; lit. running [away from] ghosts) refers to the sudden abandonment of roadside vendor stalls in Hong Kong, when the squads of the Hawker Control Team (小販管理隊 or 販管隊 in short) are coming and the vendors are either operating a stall illegally or selling prohibited goods.
Gwei refers to the Gweilo, as the hawker control officers were usually westerners in the old days.
Jau Gwei is the word shouted out to warn other vendors of the approaching squads. Hong Kong has tried to reduce illegal vendors by licensing hawker permitted places, but a large percentage of street vendors still operate illegally. The term can also be heard in Macao and China's Guangdong Province where similar situations exist with illegal street vendors.
See also
City Urban Administrative and Law Enforcement Bureau