South Vietnam, 20 Years UNESCO, December 15th, 1966, Michel Nr. SVN 375-377; Three stamps in nominals of 1D, 3D and 7D were issued in perforation 13.
Here is the mint set
and here the postally used set
Enpreuves de Luxe; STCV Roma membro del Gruppo THOMAS De La RUE Londres inscribed at bottom right.
Multiple franking of the 1D value paying an overall postage of 2D on a domestic military letter (full contents preserved) sent by a civilian in Tran Binh Trong to KBC 4100 in May of 1967, the Thu Duc Infantry School. Letters to members of the military only had to pay 50% of the standard postage rate.
Multiple franking of the 3D value (2) paying an overall postage of 6D on a domestic letter (full contents preserved) sent by a member of the military (KBC 4648/Political (Psychological) Warfare School located in Dalat) sent in October of 1971 to a civilian in Phong Dinh. Black circular KBC cachet on front.
Multiple franking of the 3D paying an overall postage of 9D on a domestic letter sent from Dalat to Nha Rang in July of 1971.
Mixed franking of the 10D and 20D Rural Post stamps together with stamps from the Crafts, Vietnamese Women, Asian Parlamentarian Union, Fishery, Rural Development, Reconstruction after TET Offensive and Caligraphy sets paying an overall postage of 188D on a registered air mail letter sent from Saigon Le Loi to Switzerland in June of 1972. A yellow sticker was added in Switzerland stating that the letter had to be picked up by July 5th, which apparently it was.
Single franking of the 7D value on a domestic registered letter sent within Saigon.
Mixed franking of the 8D WHO stamp together with the UNESCO set paying an overall postage of 19D on an international air mail letter sent from Danang to West Germany in October of 1967.
Registration Nr. 200660