law: Indian Post Office Act, 1898 
  9. Power to make rules as to registered newspapers 
  (1) The Central
  
  Government may make rules providing for the registration of newspapers for
  
  transmission by inland post as registered newspapers.
  (2) For the purpose of
  
  such registration, every publication, consisting wholly or in great part of political
  
  or other news, or of articles relating thereto or to other current topics, with
  
  or without advertisements, shall be deemed a newspaper, subject to the
  
  following conditions, namely:-
  (a) that it is published in numbers at
  
  intervals of not more than thirty-one days; and
  (b) that it has a bond
  
  fide list of subscribers.
  (3) An extra. or
  
  supplement to a newspaper, bearing the same date as the newspaper and
  
  transmitted therewith. shall be deemed to be part of the newspaper:
  Provided that no such extra or
  
  supplement shall be so deemed unless it consists wholly or in great part of
  
  matter like that of the newspaper and has the title and date of publication of
  
  the newspaper printed at the top of each page.
  Explanation.- Nothing in this
  
  section or in the rules thereunder shall be construed to render it compulsory
  
  to send newspapers by the inland post.