Pingshui Yun

[3] The system was traditionally attributed to Song dynasty scholar Liu Yuan (劉淵), whose 1252 work Renzi Xinkan Libu Yunlüe (壬子新刊禮部韻略) divided common Chinese characters in poetry into 107 rhyme categories.

The latter's contents were almost identical to Renzi Xinkan Libu Yunlüe, with the only difference being that Liu's book splits the rhyme category 迥 into two.

[4] A book unearthed from the Mogao Caves named Paizi Yun (排字韻) implies that the system was already widely circulated at the time.

[6] In the Yuan, Ming and Qing dynasties, the Pingshui Yun system was highly influential as the Yunfu Qunyu version served as the official standard in the imperial examinations.

[2] In addition to literary usage of this rime system, in early modern China when sending telegraphs were expensive, the words in Pingshui Yun were used to represent dates in order to reduce the number of characters as shown on the table on the right.