Traditionally, when there were three or four generations used to
live in the same compound, when there are tens or possibly more
than a hundred people that one needs to recognise and address
correctly, only a hierarchical system could avoid the confusion.
First of all it is extremely rude to address one’s elder by his
or her name.
A whole range of vocabulary exists to precisely identify an
uncle, as shown in the following table.
It is not uncommon that a traditional ethnic Chinese does not
know his uncle or aunt’s real name.
Terms used for the uncles are as follows:
Elder brother of your father
[bo bo]
Younger brother of your father
[shu shu]
Brother of your mother
[jiu fu]
Husband of a mother's sister 
[yi zhang]
Husband of a father's sister
[gu zhang]
Hence your third [shu] should be the third amongst your father’s
brothers, younger than your father.
Your second [guzhang] would be the husband of the second sister
of your father.
The list for aunts are as follows:
Sister of your father
[gu]
Sister of
your mother
[yi]
Wife of your father’s elder brother [bo
bo]
[bo mu]
Wife of your father’s younger brother [shu
shu]
Wife of the your mother’s brother [jiu
fu]
[jiu mu]
