Phung Van Quang, a Dao ethnic person in Na La Hamlet, Son Phu Commune, Na Hang District belongs to the descendant level of the Phung family.

There are 9 sub-groups of Dao in mountainous Tuyen Quang Province with many different family name such as Ban, Chuc, Ly, Trieu, Phung, Dang, etc. In each Dao family, people create various middle names for member generation discrimination.

Normally, giving middle names of the Dao from the 1st to 5th or 7th generation will be repeated. For examples, the Phung family (6 generations) has middle names respectively of Dung, Thanh, Xuan, Van, Kim, Chang. Meanwhile, the Ban family (7 generations) with 7 middle names, including Van, Loc, Thanh, Kim, Tai, Nguyen, Huu.

However, the middle name only applies to men. In contrast, most Dao women are given "Thi" as a middle name.

The custom of giving middle name of the Dao people in Tuyen Quang has meanings. Firstly, it indicates the hierarchic order in the families of the Dao ethnic group. Since then, they have appropriate ways to address their relatives, showing the good behavioral culture of the Dao people. Next, this naming is extremely sciential because it avoids consanguineous marriages. For instance, according to the Ban family regulations, it must be from the 5th generation and later that people in the clan are allowed to marry each other, ensuring the comprehensive development of children and lineage maintenance.