The designer's initial can be found in the bottom-right corner of the stamp. The initial M belongs to Carl Mangold.
The Universal Postal Union with headquarters at Berne, Switzerland and organized in 1874, bound many countries of the world into a single postal territory for the reciprocal exchange of mail. Delegates from the member nations meet about every five years to decide upon policy and administrative matters. Canada's membership in the Union dates from 1878. For eighty-three years at the time of this issue, despite wars and upheavals of all kinds, the Universal Postal Union has carried on its work. The U.P.U. exemplifies international co-operation at its highest level when the efforts of all ruling authorities are dedicated to constructive, peaceful work of delivering mail.
The Peace Tower on Parliament Hill, Ottawa, with a small post horn in the left upper corner.