To
celebrate the centenary of the organization, the UPU asked all member countries
to issue special stamps to commemorate this occasion.
Stamp catalogue
Ascension
Island 27
March 1974
Liechtenstein 6 June
1974
Netherlands 9
October 1974
Netherlands Antilles 9 October 1974
Niger 9
October 1974
Surinam 1
September 1974
Tunisia 9
October 1974
Union
of Soviet Socialist Republics 8
October 1974