It's a local custom.

这是当地的风俗习惯。

《牛津词典》

The young woman, after all, is their property, according to local custom.

毕竟，按照当地的风俗这名年轻妇女是他们家的财产。

youdao

According to the local custom, people tint the eggs red as gifts on a wedding day.

根据当地习俗，人们在婚礼喜庆日子把鸡蛋染成红色作为礼物。

youdao

Chicago was preparing for its own big parade and an eye-catching local custom: dying the Chicago River green.

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Two days later, in the capital of Khartoum, we walked the streets, rode a city bus to the confluence of the Blue and White Niles, chatted with dozens of Sudanese, and, after dark, found a street-food stall for a meal of goat, eaten with our fingers as per local custom.

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This changed in 2004 with the arrival of Bill Courtney, a local dealer in custom lumber, who volunteered to coach the team.

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