20 Heller Krummnussbaum.

Krummnussbaum is a small market town in Lower Austria, and like hundreds of Austrian municipalities in 1920, it printed its own emergency small-change notes — Notgeld — to compensate for the near-total disappearance of coins from circulation. The postwar coinage collapse was severe enough that even villages with no banking infrastructure of their own became de facto issuers of currency, however temporary.

The Jaksc reference places this squarely within the documented Austrian local Notgeld corpus. At the 20 Heller denomination, this is the smallest fractional unit in the Krummnussbaum series — purely a functional piece, not one of the decorative collector-targeted issues that Austrian towns produced simultaneously for the philatelic market.