In the literature on the Problem of Extraterrestrial Civilizations, besides the term SETI (Search for Extraterrestrial Intelligence), term CETI (Communication with Extraterrestrial Intelligence is also used. Historically, the term CETI appeared earlier. It was proposed by Professor Rudolph Pesek, Chairman of the Astronautics Commission of the Czechoslovak Academy of Sciences. R.Pesek was the first Cahirman of the CETI Committee of the International Academy of Astronautics (IAA). The term CETI persisted till about mid-1970s, when it was gradually replaced by term SETI. The reason for this substitution was probably the circumstance that, before talking about establishing a communication with extraterrestrial civilizations, these must be detected. Conseuqently, the search must precede the communication. Later, the CETI Committee of the IAA, too, was renamed to SETI Committee.