customary vs normative

customary

adj
  • In accordance with, or established by, custom or common usage 

  • Holding or held by custom 

noun
  • A book containing laws and usages, or customs; a custumal. 

normative

adj
  • Of or pertaining to a norm or standard. 

  • Conforming to a norm or norms. 

  • Attempting to establish or prescribe a norm. 

noun
  • A regulation imposed to preserve a norm. 

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