annotation annotation /ˌænoʊˈteɪʃən/

noun

1. The act of adding notes  ( annotating , annotation )
   the act of adding notes
   
2. A comment or instruction (usually added)  ( annotation , notation , note )
   a comment or instruction (usually added)
    His notes were appended at the end of the article
   his notes were appended at the end of the article
    He added a short notation to the address on the envelope
   he added a short notation to the address on the envelope