10 Pfennig

Schildberg — today Ostrzeszów in west-central Poland — was a small administrative district in the Prussian province of Posen, and like hundreds of similar Kreise it resorted to printing its own emergency small-change notes in 1917 when wartime metal shortages made coin circulation collapse. These Notgeld issues were authorised at the local level precisely because the central authorities could not keep low-denomination coinage in supply.

The official stamp substituting for a security feature tells you something real about the production: no specialist printer was involved, and authenticity rested entirely on that applied impression rather than any embedded protection in the paper itself.