law: Special Marriage Act, 1954 
  15. Registration of marriages
  
  celebrated in other forms
  Any marriage
  
  celebrated, whether before or after the commencement of this Act, other than a
  
  marriage solemnized under the Special Marriage Act, 1872, or under this Act,
  
  may be registered under this Chapter by a Marriage Officer in the territories to
  
  which this Act extends if the following conditions are fulfilled, namely :-
  (a) a ceremony of
  
  marriage has been performed between the parties and they have been living
  
  together as husband and wife ever since ;
  (b) neither party has
  
  at the time of registration more than one spouse living ;
  (c) neither party is
  
  an idiot or a lunatic at the time of registration ;
  (d) the parties have
  
  completed the age of twenty-one years at the time of registration ;
  (e) the parties are
  
  not within the degree of prohibited relationship :
  Provided that in the case of a
  
  marriage celebrated before the commencement of this Act, this condition shall
  
  be subject to any law, custom or usage having the force of law governing each
  
  of them which permits of a marriage between the two ; and
  (f) the parties have
  
  been residing within the district of the Marriage Officer for a period of not
  
  less than thirty days immediately preceding the date on which the application
  
  is made to him for registration of the marriage.