known vs restricted

known

noun
  • Any fact or situation which is known or familiar. 

  • A constant or variable the value of which is already determined. 

adj
  • Accepted, familiar, researched. 

  • Identified as a specific type; famous, renowned. 

restricted

adj
  • Available only to certain authorized groups of people. 

  • Only available to customers who do not belong to racial, ethnic or religious minorities. 

  • Limited within bounds. 

How often have the words known and restricted occurred in a corpus of books? (source: Google Ngram Viewer )