law: Negotiable Instruments Act, 1881 
  39. Suretyship 
  When the holder of an accepted bill of exchange enters into any
  
  contract with the acceptor which, under section 134 or 135 of the Indian
  
  Contract Act, 1872 (9 of 1872), would discharge the other parties, the holder
  
  may expressly reserve his right to charge the other parties, and in such case
  
  they are not discharged.