Some limitations exist on the power to enact ordinances. The Supreme Court of the United States has held that the United States Constitution requires that laws, including municipal ordinances, may not be arbitrary or discriminatory, and may not be unreasonably vague, so that a resident may be reasonably certain that their conduct conforms to the law. Furthermore, local governments can not delegate the power to enact ordinances to other bodies. However, they may establish fixed and certain standards for carrying out certain activities (such as home building or operating restaurants), and then delegate to subordinate bodies the power to make rules governing how residents can demonstrate compliance with these standards.