Issues in relation to which referendums are optional at the national level
Sudan
Answer
Any issue of national importance
Source
The Interim National Constitution of the Republic of Sudan (from 2005) http://www.mpil.de/shared/data/pdf/inc_official_electronic_version.pdf
ReferendumArt. 217 (1) The President of the Republic or the National Assembly, by resolution passed by more than half of the members, may refer to referendum any matter of national or public interest.
