5 Pfennig - Krotoschin

Krotoschin — now Krotoszyn in west-central Poland — was a Prussian administrative town in the Posen region that issued notgeld iron coinage during the acute metal shortages of World War I. Municipal emergency issues of this kind were authorised locally rather than by the Reichsbank, filling a genuine gap in small-denomination circulation when copper and nickel were redirected entirely to the war effort. Iron was a deliberate second choice: cheap, abundant, and deeply unpopular with the public, who found it prone to rust in pocket humidity.