It’s the Cantonese interpretation of the Vietnamese phrase “bắt đầu từ nay,” meaning “From this point forward.” But—in Hong Kong, it’s also a derogatory term for “Vietnamese person.”

The phrase passed into common usage in the late 80s and early 90s, at the height of the Vietnamese refugee crisis. The communist takeover of Vietnam and Laos led to an exodus of refugees from the territories, with Hong Kong becoming a key place of refuge. But the city—and indeed, the region—was unable to handle the influx, with refugee camps springing up across the territory.

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In 1988 the government announced a Comprehensive Plan of Action to deal with the crisis. The plan stipulated that after June 16 of that year, all Vietnamese who arrived in Hong Kong would no longer automatically be considered refugees, but instead be treated as asylum seekers—meaning that would have to apply for refugee status.

In order to spread the word, the government broadcast an announcement in (heavily Cantonese-accented) Vietnamese on RTHK radio, approximately once an hour. The first line went as follows:

Bắt đầu từ nay, một chính sách mới về thuyền nhân Việt Nam đã được chấp hành tại Hồng Kông.

Which translates as:

“From now on, a new policy regarding Vietnamese boat people has been implemented in Hong Kong.”

Hongkongers soon learned the opening phrase, turning the Cantonese transliteration into “bat lau dung laai” (不漏洞拉, the nonsensical “don’t leak hole pull”).