Zi Collection, Upper Volume Radical: Fish (yú) Page 1084, Entry 06 Pronunciation uncertain. The "History of the Tang Dynasty" (Tangshu), in its "Treatise on Carriages and Attire" (Chefu Zhi), records that during the Jinglong era, the buckle of a belt hung downwards, called a "yu wei," meaning to hang down smoothly. The "History of Song" (Songzhi) states that the "yu wei" is the same as the present-day "fish tail."