Legal provisions for optional referendums at national level

Constitution of the Federal Republic of Austria

http://?www.?ris.?bka.?gv.?at/?GeltendeFassung.?wxe?Abfrage=Bundesnormen&Gesetzesnummer=10000138

Referendum: B-VG (Bundes-Verfassungsgesetz, enacted 1920)Art. 45, 46 B-VG                   

Optional:B-VG Art. 43, Art. 60 (6)

There are 2 types of an optional referendums:

1. Referendum: Referendum is binding if it is about the adoption of a law

2. Public opinion polls: A referendum over a non-existing law is not binding