2 Mark Gefangenenlager

Hammerstein — now Czarne, Poland — housed Russian prisoners during the First World War, and like dozens of German POW camps, it issued its own internal scrip to prevent detainees from accumulating currency usable outside the wire. These camp marks circulated only within the compound and were theoretically redeemable at the canteen. In practice, redemption at war's end was chaotic, and most surviving examples were simply pocketed by departing prisoners or camp staff rather than exchanged.

Gefangenenlager issues are notoriously unattributed in contemporary records — denomination and camp name are often the only reliable data points a collector gets.