5 Pfennig - Warendorf

Warendorf, a small Westphalian town on the Ems, issued notgeld coinage in 1920 during the acute small-change shortage that followed the First World War — a crisis severe enough that hundreds of German municipalities briefly became their own monetary authorities. Iron was the practical choice: cheaper to strike than zinc, more available than copper, which remained strategically restricted in the immediate postwar years.

The Funck reference places this among a documented series from the town, suggesting coordinated municipal issue rather than emergency improvisation.