What is engraved on the ceiling ruler?

The ceiling ruler is a Taoist instrument, also called a ruler. Its shape is a short square stick with a spell engraved on all sides. Rulers are made of mahogany or iron. The ceiling rulers are mostly quadrangular, and the six sides are engraved with Twenty-eight Nights, Sun and Moon, Purple Taboo (the name of China Emperor Wei Zi), Ceiling Taboo (the name of Tian Pengyuan Shuai), Six Stars in the South and the Big Dipper (namely the King of the Southern Star and the King of the Big Dipper). In the eastern Jin dynasty's mythical novel "Searching for the Gods", the viewpoint that "the southern bucket is reborn and the Beidou is dead again" was put forward. Waving a ruler means respectfully inviting Tian Pengyuan Shuai to the altar to exorcise evil spirits.