50 Colones Centenario Banco de Costa Rica

The "Centenario" suffix in this series title marks the centenary of the Banco de Costa Rica, the commercial bank that predates and is entirely separate from the issuing authority here — the Banco Central. The note commemorates an institution the Central Bank regulates but did not absorb, an unusual distinction worth understanding before attributing the naming to national rather than banking history.

Thomas De La Rue's work for Central American issuers during this period was prolific, and the P#251 series ran across an eight-year window with no major design revision. Watermarking alone as the primary security feature was already considered thin by the late 1970s, when most comparable issues were incorporating security threads.