The production team called the fake Slavic-style language in the original *Mission: Impossible* series “Gellerese.”
The invented name honors creator and producer Bruce Geller. The series often placed the IMF team in fictional Eastern European or Slavic-looking settings, where signs, labels, uniforms, and documents needed to suggest a foreign regime without committing the production to a fully authentic language.
Gellerese was designed to look readable to viewers who did not speak Slavic languages. The result mixed visual cues and plausible-looking words rather than functioning as a real national language. The device helped establish the show's Cold War atmosphere while also allowing the production to create fictional countries and institutions.
This should not be confused with Esperanto, which is a real constructed international language, or Newspeak, George Orwell's fictional language from *Nineteen Eighty-Four*. The series did sometimes use genuine languages and real regional references, but its recurring fake Slavic-style shorthand was known as Gellerese.