The question of substantive limits is most important in the case of constitutional revisions. Most constitutions do not prescribe substantive limits to their revision, but this does not exclude the possibility of such limits existing, whether they be extrinsic (international law or some of its rules) or intrinsic, entailing the precedence of certain constitutional provisions over others. This is not the place to enter into a doctrinal debate but rather to establish to what extent national legal systems recognise such limits to the constitutional referendum.