Normalizace

Normalizace was the period that followed the Soviet-led invasion of Czechoslovakia in 1968 that brought an end to the Prague Spring.  

"Normalisation" began in 1969 and lasted 20 years until the Velvet Revolution in 1989. 

It was the systematic restoration of hard-line control of the communist party in Czechoslovakia characterised by political repression, censorship, and enforced societal conformity.

In April 1969, Gustáv Husák replaced Alexander Dubček as First Secretary of the Communist Party.  There was no Stalin-style executions or gulags but rather administrative and bureaucratic oppression to keep people under control.  

• About 500.000 people who had supported the Dubček's reforms were kicked out of the communist party.  Many were demoted to manual labour positions regardless of their education or expertise.  
• Loyalty declarations were required to:
• Keep your job
• Study at university
• Hold cultural or academic positions
• Travel abroad
• Censorship was fully reinstated.
• Books, films, and music from the reform era were banned
• Artists, writers, musicians, and filmmakers were blacklisted
• Independent organisations were dismantled
• StB surveillance increased dramatically with informants recruited, or coerced to inform, in workplaces, apartment buildings and student dorms

Normalisation relied on quiet pressure, social isolation and the fear of consequences to keep people in check.  

Basically that the system will leave you alone so long as you don't challenge the system.  

This helps explain why today Czechs are often so skeptical towards authority, don't trust political slogans and value personal freedom.