入门问讳

Explanation: To visit the ancient people, first ask him leaves his father's name in order to talk taboo. Also refers to ask what is taboo. 　　Usage: Partial official; as object clause; refers to the custom of respect for others 　　Source: Han Dai Holy "Book of Rites ceremony song": "into the ban and asked unexpectedly, into the country and asked the customs, entry and asked the taboo." Brief Account Shu: "'entry and asked taboo' by the door, the owner of the door; taboo , the owner Zuxian Jun names, should be the prophet, prefer to give to stay away also. "