German ostmark
Ostmark (German: [ˈɔstmaʁk] ) is the name given to a currency denominated in Mark which was issued by Germany in 1918 for use in a part of the eastern areas under German control at that time, the Ober Ost area. The currency consisted of paper money issued on 4 April 1918 by the Darlehnskasse Ost in Kowno (Kaunas) and was equal to the German Papiermark.