Issued by Poland in 1967, this 60 groszy stamp commemorates the 15th anniversary of the Organizacja Współpracy Łączności Krajów Socjalistycznych (OIRT). The bold yellow “15” frames a central radio transmission symbol, representing international broadcasting cooperation among socialist nations. The modernist purple and grey color scheme reflects the technological optimism of the 1960s. Inscribed “Warszawa 1967,” it highlights Poland’s active role in telecommunications development during the Cold War era. A strong thematic addition for collectors of radio, communications, Cold War, and socialist-era philately.