gǔ dài / shū xìn / lǐ / cháng yòng / zūn jūn / lái / chēng hū / duì fāng / de / fù qīn

古代书信里常用'尊君'来称呼对方的父亲。

In ancient letters, 'zunjun' was often used to refer to the other person's father.