universal vs unwritten

universal

adj
  • Of or pertaining to the universe. 

  • Useful for many purposes; all-purpose. 

  • Unlimited; vast; infinite. 

  • Common to all members of a group or class. 

  • Common to all society; worldwide. 

noun
  • A characteristic or property that particular things have in common. 

unwritten

adj
  • Implicit or understood but not formally articulated. 

  • Not written. 

  • Oral or otherwise communicated without writing. 

  • Containing no writing; blank. 

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