commentary vs formal parameter

commentary

noun
  • A series of comments or annotations; especially, a book of explanations or expositions on the whole or a part of some other work. 

  • An oral relation of an event, especially broadcast by television or radio, as it occurs. 

  • A brief account of transactions or events written hastily, as if for a memorandum. 

formal parameter

noun
  • An abstract representation, typically including a name and a type, of a parameter expected to be passed to a method or function. 

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