These two octagonal (8-sided) stamps were issued in January 2009 by North Korea to commemorate the 2008 Beijing Olympics Games. It is unusual in that they consist of two playable DVDs with values of 300 Won and 500 Won, respectively. The DVDs are enclosed in a package and contain Korean songs and dances.
“The First Digital Versatile Disc Stamp of the world” is mentioned on the package label.
Subsequent to their release, North Korea issued a second version with round CDs. The phrase on the package label was changed to “The first Compact Disc video stamp of the World”.
Even later, a third version was issued. It reverted back to the original octagonal shape and the phrase on the package label remained “The first Compact Disc video stamp of the World”.
It is unknown how many of each version was issued. Many years ago, I managed to buy a set of the first DVD version to include in my collection of unusual stamps. I would have like to purchase a set of the second and third versions, but I have not seen any for sale since.
Images and description of each issue are courtesy of Philateliquely Moi (website: http://philaquelymoi.blogspot.ca/search/label/DVD%20Rom%20Stamps)