advisory vs announcement

advisory

noun
  • A warning. 

adj
  • Able to give advice. 

  • Containing advice; advising. 

announcement

noun
  • An act of announcing, or giving notice. 

  • That which conveys what is announced. 

  • The content which is announced. 

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