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

Dominican Republic
Answer
This issue has not been regulated yet by a special law.
Source
Constitution of theDominican Republic 2010 (Constitución de la República Dominicana)
http://aceproject.org/ero-en/regions/americas/EC/ecuador-constitucion-politica-de-ecuador-2010
Comment
The DD instruments are embedded in the newConstitution enacted in 2010, but have not yet been regulated by any specificlaw as ordered by the Constitution itself.