Many different types of philatelic products have been created over the years by many different organizations and individuals. In China the so-called “Non Postal Value Souvenir Sheets” are one specific example of a type of such a product. They were (and are?) created on a very large scale, but they are relatively unknown outside of East Asia.
D&O Trading (Zuidhorn, the Netherlands) have a very comprehensive listing of these sheets. Interestingly, there are also sheets directly related to Korea. It is easy to find them by searching for them on the D&O website. Most of the examples were created in relation to the 2002 FIFA World Cup held in both Korea and Japan.
But with 2019 being such an important year in Korean history this depiction of the Taegeukgi in the PhilaKorea 1994 logo simply couldn’t be ignored:
This is how D&O lists this particular sheet:
Unfortunately Ton van Doornen from D&O Trading when asked for more information regarding this sheet answered that despite the high serial number suggesting many were produced he doesn’t own this sheet himself. If anyone has more information (or other examples!) please leave a message in the comments below.