One specific means of exercising oversight regarding use of local referendums is designation of a supervisory authority, which exists for instance in Belgium. Automatic prior review of the question put to the vote may also be performed by a judicial authority: in Italy, the special office of the Court of Cassation gives decisions concerning referendums on changes to regional boundaries or the creation of new regions; in Portugal, the Constitutional Court obligatorily rules on the constitutionality and lawfulness of the question put to the vote, in terms of both form and substance.