law: Indian Post Office Act, 1898 
  28. Registration of postal articles 
  The sender of a postal
  
  article may, subject to the other provisions of this Act, have the article registered
  
  at the post office at which it is posted, and require a receipt therefor, and
  
  the Central Government may, by notification in the Official Gazette, direct
  
  that, in addition to any postage chargeable under this Act, such further fee as
  
  may be fixed by the notification shall be paid on account of the registration
  
  of postal articles.