Issues in relation to which referendums are optional at the national level

Namibia
- Constitutional amendments
- Any issue of national importance
TheConstitution of the Republic of Namibia
(adoptedin 1992)
http://www.orusovo.com/namcon/
Article 63(2). (Issues of National Importance)
TheNational Assembly shall further have the power and function, subject to this
Constitution:
g)to initiate, approve or decide to hold a referendum on matters of national concern;
Article132 (3a) (Consititutional amendments)
Notwithstanding the provisions of Sub-Article(2) hereof, if a bill proposing a repeal and/or amendment of any of theprovisions of this Constitution secures a majority of two-thirds of all themembers of the National Assembly, but fails to secure a majority of two-thirdsof all the members of the National Council, the President may by Proclamationmake the bill containing the proposed repeals and/or amendments the subject ofa national referendum.