Guangyun (Guangyun) splits at "yu" and "bi," Jiyun (Jiyun) and Yunhui (Yunhui) split at "yue" and "bi," and Zhengyun (Zhengyun) splits at "yi" and "lü," pronounced "yu." Yipian (Yipian) explains it as a great wind. Yu Chan's "Ode to the Sea" states: The hundred rivers gather like chariot spokes, the four great rivers crisscross. Deep and vast, the water surges, waves scatter and rise like domes. Han Yu's poem writes: Like newly removed earwax, thunder approaches, a hurricane-like great wind. Additionally, the "Treatise on Officials" in the History of the Tang Dynasty (Tangshu) records the [Yulian Sea Route]. There is also [Xie Yulian], the name of a foreign country. Its original name was Caojuzha, and it was changed to its current name during the reign of Empress Wu Zetian.