Claim: The logo of HRT 1 (operated by a Croatian public broadcasting company) from 1956 to 1970 has stylized white circles in square making "RTZ"; which evolved in to a yellow RTZ with small captions from 1972 to June 1990.
Evidence: Hrvatska radiotelevizija (English: Croatian Radiotelevision) or simply HRT is a Croatian public broadcasting company. 1956–1970 Stylized white circles in square making "RTZ" . Yellow RTZ with small captions. 1972–June 1990