law: Negotiable Instruments Act, 1881 
  15. Endorsement 
  When the maker or holder of a negotiable instrument signs the
  
  same, otherwise than as such maker, for the purpose of negotiation on the back
  
  or face thereof or on a slip of paper annexed thereto, or so signs for the same
  
  purpose a stamped paper intended to be completed as a negotiable instrument, he
  
  is said to endorse the same, and is called the "endorser".