字and号are only widely used in ancient China,but still many people use them in the modern times(before the World War 2).As for 乳名and小名，they are used all the time,even today.老大，老二，老三only indicate the different ages among brothers or sisiters,no gender differences(This is one of those several situations,the three words can be also used in other relationships,like friends.)Hope this can help you.:)

There is nothing abnormal about having a 字 as one of one's many names. Mao Zedong, 字润之。 Zhou Enlai, 字翔宇。 There are 历史 and 阶级性 embedded in your question. You need to delve more into 知识分子、阶级斗争 and 破四旧 in your Chinese studies to understand why Zack used the word "normal people" and how during different periods of history different kinds of people were and are not regarded as normal. Of course, in English-speaking countries, arbitrarily labelling people as "not normal" is often regarded as narrow-minded and offensive. It is true that as a result of the proletarian revolution, the traditional practice of people having 字 is not as popular as before. With the revival of Confucianism as a politically correct theology for 1.4 billion people, however, one cannot predict whether 字 will after all come back into fashion.

We all have "姓"“名”.Some people have "字"“号”,but mostly people only have "姓""名".There are not many care about the differences between "名""字".I have "姓""名""字" because we keep a genealogy......though there is no capping ceremony.

There's no 字and号 in modern times any more for normal people,only masters in literatures or ancient times. Yes, we do have nick names during our childhood. 老大，老二，老三 could be used for both sons and daughters.

Hi wang haoyu, My Chinese is still very lousy but I was able to understand that you would like to me to respect Confucius (Kong Zi). Of course, I respect him but I only learned about 老二 through a native Chinese (Han Chinese) teacher who was talking about how Confucius was nicknamed during the Communist Revolution era. I did not mean to disrespect.