Democracy in ancient Greece, during the reign of Cleisthenes, implemented the "exile law of pottery tablets". At the annual citizens' meeting, if citizens think that someone's behavior harms citizens' interests and threatens the democracy of the city-state, they write his name on the pottery piece and then put it in the pottery jar. A piece of pottery is equivalent to a vote. If this person gets more than 6000 votes, it means that most of them pass and he is deported for ten years. The cover is "Pottery Piece".