If you were wondering why Thousand Autumns or other Chinese novels sometimes have so many different names for the same character, then it would be helpful to know about xìng (姓), shì (氏), míng (名), zì (字), and hào (号).
Here’s a layman breakdown.
Note: I do not claim to be an expert, and just am explaining this based on my understanding and some internet trawling.
1. Surname: xìng (姓)
to identify ancestry, people of the same surname weren’t supposed to marry one another to avoid consanguinity.
2. Clan: shì (氏)
to identify one’s family and clan, which also may represent the social status (e.g. Yunmeng Jiang Clan). People from the same ancestry (they would share the same surname) may migrate to different places and start families with their own clans; it’s like referring to a different branch of the extended family.
Also, prior to the Qin dynasty, China was largely a (feudal) society. As fiefdoms were divided and subdivided among descendants, so additional sub-surnames known as shì were created to distinguish between noble lineages according to seniority, though in theory, they shared the same ancestor. In this way, a nobleman would hold a shì (氏) and a xìng (姓). xìng (姓), however, was more important than shì (氏) .
The format is generally “Place/location, shì (氏)”. Yan Wushi is said to be of the Chen Commandery’s Xie Clan, and Wang Zhuo identified himself as from the Kuaiji Wang family. Hence one can share the same surname or xìng (姓), but a different shì (氏) – which indicates that they share the same ancestors, but there was a divergence where they separated and started their own families, thus bearing a different shì (氏).
3. Name: míng (名)
one’s birth name from parents.
4. Courtesy Name: zì (字)
one’s formal/courtesy name is given after one reaches adulthood (20 years old for a man) by a parent or a teacher. It is usually used to express virtues or the meaning of one’s first name. For example, with Li Qingyu, Qingyu (青鱼, qīng yú) is his name (名), and Mingchen (明辰, míng chén) is his courtesy name. One would use this to address someone instead of their real/birth name in order to show politeness. Generally, you would only use someone’s birth name if you are of higher social status (e.g. parents, elders, or very close.)
According to the Book of Rites, after a man reached adulthood, it was disrespectful for others of the same generation to address him by his given name, or míng (名). Thus, the given name was reserved for oneself and one’s elders, whereas the zì (字) would be used by adults of the same generation to refer to one another on formal occasions or in writing; hence the term “courtesy name”.
5. Alias / Title: hào (号)
a formal alias that one may take for themselves.
For example, taking the example of Su Dongpo (a Chinese poet of the Song dynasty). His name or míng (名) is Su Shi (苏轼, sū shì), and his zì (字) are either Zizhan (子瞻, zi zhān) or Hezhong (和仲, hé zhòng). His self chosen alias or zì hào (自号) is Dongpo Jushi (东坡居士, dōngpō jūshì), and his Taoist/dao alias (道号) is Dongpo-daoren (东坡道人, dōngpō dàoren). Most people call him Su Dongpo.
(Sassy: This is why Yan Wushi’s changing of his family name is so disturbing to me because he changed his xìng (姓), which is similar to denying his ancestry, as well as his birth name, which is a gift from one’s parents. I assume that the Demonic Sovereign is an alias that was given by others, since he said himself that he dislikes the moniker.)
It doesn’t seem like a lot of the characters use their zì (字) or courtesy name in Thousand Autumns, unlike in MDZS. One such example Jiang Cheng: jiāng (江) is his surname, chéng (澄) is his birth name, and he’s also known by his courtesy name of wǎn yín (晚吟) and his alias/title, Sāndú Shèngshǒu (三毒圣手). He is from the Yunmeng Jiang Clan (云梦江氏, yún mèng jiāng shì).
(Sassy: When an elder calls you by your surname + name, or surname + courtesy name -> you’re probably in deep trouble! )
This politeness is also why other people use daozhang, zhenren, and other titles or honorifics instead of the person’s name.
Yan Wushi directly giving a diminutive nickname like “Ah-Qiao” and using it in public is extremely overly familiar, and implies that he is either family or a very intimate close friend. But Shen Qiao actually responding/letting it slide, is practically implicit acceptance or acknowledgment. Even when Bai Rong and Yuan Xiuxiu were flirting with Shen Qiao, they would only refer to themselves humbly. Or at most use a sultry Shen-lang or langjun (郎君）which is still within… albeit barely within propriety.