Five Percent Rule
The Five Percent Rule (五分法) was a special ordinance, No. 1442, passed in Kien-k'ang in 1955 restricting the amount of land that could be granted to religious structures in urban planning, to 5% of the city's total area (then) of 38.76 km².
The preamble of the ordinance states that the rule was passed to protect the rights of habitation for non-religious adherents and to prevent religious groups from engaging in land speculation. But many historians believe the rule was enacted to suppress new religious movements by denying land for their worship or proselytization. The amount of land already dedicated to religious uses as of 1952 was 12.3%, meaning no land could be converted to religious uses, while the land already used this way could remain under a grandfather clause. Thus, short of acquiring land from existing religious bodies (their competitors), new religious movements could not establish a public meeting place. The ordinance implicitly protected the religious bodies that already owned land authorized for religious uses, which in the early 50s was only a few large institutions.
A suit was brought in the Supreme Court of Themiclesia challenging the city's power to make such a regulation, on the grounds that to outlaw a specific use of a piece of land is to remove the potential value derived from that use in that piece of land. The court, however, rejected the suit, saying that the city's zoning regulations did not remove actual value of the land, which can only be based on its value of its lawful uses, rather than for all possible uses including unlawful ones. Additionally, no piece of land that the plaintiffs owned lost its permission to house a church as a result of Ordinance No. 1442, so they lacked a damaged interest to seek compensation for anyway.