5 Francs - Camp de prisonniers de guerre de Nanterre

Nanterre operated as a German prisoner-of-war camp during the First World War, and like many French camps of the period it issued its own internal scrip to allow inmates to make purchases within the enclosure without handling official French currency. These camp notes were a deliberate administrative measure — keeping real money out of prisoner hands reduced escape incentives and simplified accounting. The grey paper on this denomination is characteristic of wartime material shortages rather than any design intention.