The choice of a courtesy name was significant, intended to express moral integrity and respect within the cultural context.
Thus, for example, Gongsun Qiao's courtesy name was Zichan (子產), and Du Fu's was Zimei (子美).
It was also common to construct a courtesy name by using as the first character one which expresses the bearer's birth order among male siblings in his family.
The characters commonly used are bo (伯) for the first, zhong (仲) for the second, shu (叔) for the third, and ji (季) typically for the youngest, if the family consists of more than three sons.
[citation needed] Prior to the twentieth century, sinicized Koreans, Vietnamese, and Japanese were also referred to by their courtesy name.