0,50 Koruna Československá (= 50 Haléřú)

Tuzex was a Czechoslovak state-run hard currency chain that allowed access to Western goods — electronics, clothing, alcohol, consumer items unavailable through normal retail — in exchange for foreign currency or bony, the internal vouchers these notes represent. Tuzex bony were not legal tender and carried no exchange guarantee from the state banking system; they functioned as a parallel scrip tied entirely to the Tuzex store network.

This 50-haléřů denomination is among the lower fractional values in the series, which suggests it was introduced to handle small-change transactions within stores rather than bulk purchasing. The guilloche underprint was a modest but deliberate anti-counterfeiting measure — forging Tuzex bony was prosecuted as currency fraud despite their unofficial status.