advisory vs instructive

advisory

adj
  • Containing advice; advising. 

  • Able to give advice. 

noun
  • A warning. 

instructive

adj
  • Conveying knowledge, information or instruction. 

noun
  • A case in the Finnish and Estonian languages. It expresses the means or the instrument used to perform an action. 

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