append vs tag on

append

verb
  • To hang or attach to, as by a string, so that the thing is suspended 

  • To add, as an accessory to the principal thing; to annex 

  • To write more data to the end of a pre-existing file, string, or other object. 

noun
  • An instance of writing more data to the end of an existing file. 

tag on

verb
  • To hover an RFID device such as a smartcard over a receiver, often with a graphical user interface, in order to make a payment or gain access to the vehicle. 

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