They also have their unique research value to language history, genealogical classification, ethnic history and culture.

中国的濒危语言对语言史、语言谱系分类以及民族历史文化都有其独特的研究价值。

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The inventory was made on two levels, national and regional-local according to the existing administrative divisions, and combined the territorial principle with classification according to ethnic and religious background as these two factors often coincided.

UNESCO: Intangible Cultural Heritage