Following the official dress edicts of 1759, the so-called "twelve symbols" connoting imperial authority began to appear on certain of the emperor's formal and semiformal robes. The symbols are specifically paced: sun, moon, mountain, and constellation emblems are positioned symmetrically around the neckband, and the other eight symbols are arranged on the front and back of the robe. In theory, only the top members of the royal family-emperor, empress, empress dowager, and crown prince could wear twelve-symbol robes.