Cinnabar system, also called "Cinnabar System" or "Cinnabar Dot mole", is a procedure in the opening ceremony of ancient schools.
The specific method is that the teacher holds a brush dipped in cinnabar and points a red dot like a mole on the students' eyebrows. Because "mole" and "wisdom" are homophonic, "cinnabar Dot mole" actually means "wisdom", which means opening wisdom. I hope that in the future study, students can be discerning and sensible at one point.