10 Kruna

Pick 6A is a converted Austro-Hungarian note — specifically a pre-existing krone issue overstamped for use in the newly proclaimed Kingdom of Serbs, Croats and Slovenes after 1918. The new state had no printing infrastructure ready, and the provisional stamp was the fastest available solution to distinguish Yugoslav-controlled currency from the flood of unstamped Austro-Hungarian paper still circulating across the former empire's dissolved territories.

The stamping process was rushed and inconsistently applied, which accounts for the wide variation in stamp placement and impression depth seen across surviving examples. Forgeries of the overstamp were a documented problem almost immediately.