The purpose of this study is to analyse those code words and euphemistic expressions used during the Cold War to protect Anglo-American communications intelligence (Comint). It is explained how the code word security system worked between 1946 and 1999, while at the same time showing how these codes and expressions can be interpreted to understand documents and information concerning the Anglo-American Comint on the Congo, Bolivia, Indonesia, South Vietnam and China in the 1960s.