Today’s word is “definitives”. Definitives are the basic set of postage stamps that are in circulation at any one time. In the Soviet Union, these tended to be issued as a set based around consistent themes over the years: workers; engineers; youth; science and peace, for example.
1966 saw the production of the 11th set of definitives for the Soviet postal system. This one conveys the notion of peace – the three letter Cyrillic word that looks like MNP translates as either “world” or “peace” and the dove is a widely recognised peace symbol. Soviet use of the dove as a peave symbol was met with justified cynicism by the US and its allies.
https://en.wikipedia.org/wiki/Definitive_stamp
https://en.wikipedia.org/wiki/Soviet_influence_on_the_peace_movement
Stamp of the Day 