Brother-in-law is a kinship term. Brother-in-law, that is, brother-in-law, will also be called brother-in-law or brother-in-law when addressing his wife and brother in some places.
The relationship between oneself and his wife and brother belongs to the in-laws relationship between relatives, and the address can be divided into oral and written language. Spoken language is a kind of address that follows the wife's address, while written language is a more formal address.
When addressing his wife's father, he is called "father" in spoken language and "father-in-law" in writing.
When addressing his wife's mother, he is called mother, queen and mother in spoken language and mother-in-law in written language.
When addressing his wife's brother, he is called brother in spoken language and brother-in-law and brother-in-law in writing.
When addressing his wife's brother, he is called brother in spoken language and brother-in-law and brother-in-law in writing.
When addressing his wife's eldest sister, she is called elder sister in spoken and written language.
When addressing his wife's elder sister, she is called elder sister in spoken language and sister-in-law and aunt in written language.
When addressing the wife of the wife's brother, it is called Sister-in-law in spoken language and Uncle-in-law and Uncle-in-law in written language.
When addressing his wife's brother-in-law, he is called brother-in-law in spoken language and brother-in-law in writing.
When addressing his wife's brother-in-law, he is called brother-in-law in spoken language and uncle-in-law in writing.
When addressing his wife's brother-in-law, he is called brother in spoken language and brother-in-law and sister-in-law in written language, and needs to be called brother-in-law.
For the wife's peers or younger generations, you can also call them by their first names directly when addressing them in spoken language.