appellation vs initials

appellation

noun
  • A name or title by which someone is addressed or identified; a designation. 

  • A geographical indication for wine that describes its geographic origin. 

initials

noun
  • An abbreviation of a person's name, constructed by taking the initial letters of first, last, and sometimes middle name(s). See monogram 

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