clipboard vs padding

clipboard

noun
  • A flat piece of rigid material, such as card or plastic, with a clip at one end under which papers can be held. 

  • A buffer in memory where the user can store data temporarily while transferring it from one place within an application to another or between applications. 

padding

noun
  • Soft filling material used in cushions etc. 

  • Extra characters such as spaces added to a record to fill it out to a fixed length. 

  • Extraneous text added to a message for the purpose of concealing its beginning, ending, or length. 

  • Anything of little value used to fill up space. 

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