As for how this rule was handed down, I think it is mainly a convention. Our ancestors first decided on some words, and then as descendants, we chose different words according to the traditions left by our ancestors, so as to classify them according to the selected words.
since our promotion, we have found that people's awareness of their peers has been significantly enhanced. For example, all the 17 sons of Emperor Wu of Qi have the word "Zi" embedded in their names, and all of them use the word "Cloud". Such as Xiao Ziliang word Yunying, Xiao Ziqing word Yunchang, etc. Another example is the six sons of Xiao Ben (M), the younger brother of Emperor Wu, whose names are all embedded with the word "Zi", but all the words use the word "Jing" to indicate that they are brothers of the same generation as the sons of Emperor Wu. Such as Xiao Zilian's word Jingai, Xiao Ziyun's word Jingqiao and so on. From this we can see their seniority, and it seems that the classification is clearer, and the seniority is also very clear, and how to use it is still very particular.
The word generation school of genealogy is used to strengthen the patriarchal clan system, so its words fully reflect this purpose. There are three main types: one is virtue or auspicious words, such as virtue, benevolence, Ming, filial piety, happiness, Lu, Ji, Xiang and Xian; The second category is the words that hope the clan will continue and prosper, such as: Yong, Chuan, Chang, Sheng, Xing, Delay, Succession, Inheritance, etc. The third category is the words that remember the ancestors and praise the kindness of the emperor, such as: Ze, Zu, Xian, Rong, En, Xi, Qi, Xian and so on.
And we all know that people's names are very important to a person. Those big families are still very concerned about the use of words for generations in order to ensure the clarity of their families' generations and the purity of their blood. As for people who use different words in different generations, there are still different rules. The words used by Confucius' family are mainly in strict accordance with the emperor's regulations, while Zhu Yuanzhang's descendants are based on the principle that Jin Mu's fire, water, soil and five elements are mutually reinforcing. Finally, it is emphasized that women do not participate in the use of words for generations.