The Kōsatsu (Japanese: 高札, literally "High plaque"), also called Seisatu (Japanese: 制札, literally "Controlling plaque"), was the public notice of the han-lord's or shogun's proclamations in the Japanese history. They were the local or nationwide laws written on the wooden plate, placed in the kōsatsu-ba of the shukuba or (関所), the border between han, where there was frequent traffic. The kōsatsu has been used from the late Nara Period of the Japanese history. One of the kosatsu in the Edo Period was on prohibiting Christianity.