A ducat was a form of Human currency from planet Earth's history. Ducats were often referenced in the works of William Shakespeare. (TOS novel: The Fearful Summons)

Types of currency
materials	acta crystal • gold • latinum • ludugial gold • silver
units	bilbok • cent • credit • darsek • dejebbit • dirak • dollar • drokna • ducat • galorine credit slip • ilec • kern • klon peag • laertian dinar • lek • lita • notch-rock • prime transfer authority • quatloo • sakto • sous • szeket • t'chak • talon • tri-esta