The ancient emperors had three palaces and six courtyards, with countless concubines and palace maids. While indulging in extreme pleasures, the emperor, who was at the "supreme" position, would apply certain selection and restrictions on the proliferation of "dragon sons and dragon grandsons." According to "A Grand View of Qing Dynasty Wild History • Remnants of the Qing Palace," after the emperor had intercourse with a concubine, the head eunuch of the Respectful Affairs Room "must kneel down and ask for orders, saying 'to keep or not to keep?' If the emperor says not to keep, then the chief eunuch will slightly press the concubine's posterior acupoint, and the dragon essence will all flow out; if he says to keep, then the date, month, and time when the emperor visited a particular concubine will be recorded in writing as evidence of possible pregnancy, and this is referred to as the "ancestral fixed system" within the palace禁区." This method of slightly pressing the concubine's posterior acupoint to make the semen flow out was an ancient palace "emergency contraception" remedy after sexual intercourse. Its effectiveness, however, due to a lack of detailed records in the relevant imperial "daily chronicles," this article will temporarily refrain from commenting.