50 Won

North Korea's 1978 note series was issued under tight state control at a time when the DPRK was attempting to project economic self-sufficiency while actually relying heavily on Soviet and Chinese financial support. The 50 Won denomination sat at a meaningful level within the domestic hierarchy — high enough to matter in a rationed economy where most transactions were constrained by the Public Distribution System rather than market exchange.

Pick 21A is distinguished from the related 21B by serial number font variations, a detail that points to mid-run production changes at the Pyongyang printing facility. These distinctions matter more here than in most series, since North Korean notes rarely surfaced outside the country before the 1990s and provenance is almost always uncertain.