Secret Marks on the Banknotes of Rostov-on-Don

Figure 4

 
Detail from the green border of two 250-ruble notes. The upper section of the image shows the border from a note of the initial release and the lower section shows the border from a note issued by the Bolsheviks. Observe the small ovals above and below 250 in the lower section; these are the secret marks.

© Peter Symes