Issues of sub-national referendums regulated at the national level

Electoral Commission Act (Act 51 of 1998)http://www.elections.org.za/content/WorkArea/DownloadAsset.aspx?id=987

Section 2 Application of Act

(2) Notwithstanding anything to the contrary in any other law contained, the President may, after consultation with the Commission, by proclamation in the Gazette—(a) declare that a referendum shall be held in order to ascertain the views of voters on a matter specified in the proclamation;(b) determine that the referendum shall be held in the Republic, or in a part of the Republic specified in theproclamation, on a day or consecutive days and, subject to this Act, during the hours so specified;(c) determine who shall be entitled, in accordance with this Act, to vote at the referendum; and(d) determine what question or questions to ascertain the views of voters, must appear on the ballot paper.

The legislation does not explicitly specify issues of sub-national referendums, merely stating that the President can determine whether the referendum will be national or if it will be limited to the part of the Republic that is specified in the proclamation