Deeds for land and houses in Ming and Qing China name 中见人, middlemen and witnesses who arranged the sale and signed the deed. One Qing deed studied by the legal historian You Chenjun lists five middlemen and an official broker, who “all signed.” It contains the formula: “Lest there be no proof later, this deed is drawn up as evidence.”
A dictionary defines 中人 as a person who stands between two sides to mediate, to witness or to introduce a sale.