U+5B57 CJK Unified Ideo­graph-​5B57

The Wikipedia has the following information about this codepoint:

A courtesy name (Chinese: 字; pinyin: zì; lit. 'character'), also known as a style name, is an additional name bestowed upon individuals at adulthood, complementing their given name. This tradition is prevalent in the East Asian cultural sphere, particularly in China, Japan, Korea, and Vietnam. Courtesy names are a marker of adulthood and were historically given to men at the age of 20, and sometimes to women upon marriage.

Unlike art names, which are more akin to pseudonyms or pen names, courtesy names served a formal and respectful purpose. In traditional Chinese society, using someone’s given name in adulthood was considered disrespectful among peers, making courtesy names essential for formal communication and writing.

Courtesy names often reflect the meaning of the given name or use homophonic characters, and were typically disyllabic after the Qin dynasty. The practice also extended to other East Asian cultures, and was sometimes adopted by Mongols and Manchus during the Qing dynasty. The choice of a courtesy name was significant, intended to express moral integrity and respect within the cultural context.