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

Congo, Democratic Republic of
Answer
None
Source
Constitutionof the Democratic Republic of Congo
(Adoptedin 2006, last amended in 20/01/2011)
http://democratie.francophonie.org/IMG/pdf/Constitution_de_la_RDC.pdf
http://www.constitutionnet.org/files/DRC%20-%20Congo%20Constitution.pdf
(Official English translation)
Comment
Constitution does not provide for optional referendum.