Section 455(2) in The Calcutta Municipal Corporation Act, 1980
(2)An error of fact or substance in any such register may be corrected by any person authorised as aforesaid by entry in the margin, without any alteration of the original entry , upon production to the Municipal Commissioner, by the person requiring such error to be corrected, of a declaration on oath setting forth the nature of the error and the fact of the case, made before a Magistrate by two persons required by this Act to give information concerning the birth or death with reference to which the error has been made or, in default of such persons, by two persons having knowledge of the case, and certified by such Magistrate to have been made in his presence.