North Korea, 1978: A set of 5 items featuring various postmarks—4 stamped and 1 unstamped—with a face value of 10 Won.

I. Basic Issuance Information

Dimensions：150mm × 75mm, no built-in watermark, traditional intaglio offset printing.

Unified Front Design

Main Design：The Chollima statue at Mansudae, Pyongyang, a symbolic representation of North Korea and embodying the spirit of rapid development exemplified by the "Chollima Movement"; North Korean national emblem in the upper left corner, the full name of the Central Bank of North Korea above, and serial numbers printed on both sides; Overall warm brown-yellow background, surrounded by geometric security features, with the denomination "10" marked in each corner.

Uniform Background Image on the Reverse Side: The Pyongyang port industrial area features a riverside landscape including docks, factory buildings, chimneys, and river navigation, showcasing the industrial development of the time.

The five banknotes are distinguished by the color of the square verification stamp on the right side of the reverse side, corresponding to different batches/purposes:

First banknote：No colored square stamp, original unstamped version;

Second banknote：Green square verification stamp (P20b);

Third banknote：Orange square verification stamp;

Fourth banknote：Red square verification stamp (P20a);

Fifth banknote：Blue square verification stamp (P20e).

II. Origin of Different Colored Stamps

The different colored stamps are verification marks added later to distinguish the distribution channels, verification batches, and special purposes of these banknotes (some used for foreign exchange, commemorative exports, and internal verification and classification); Unstamped versions are original circulating versions; the colored stamped versions are mostly added later for targeted export and collection batches, and are also the core basis for distinguishing the versions of this set of banknotes for collectors.