The declaration barred under the proviso to Section 24(2) of the Special Marriage Act, 1954 relates to:

The proviso to section 24(2) says no declaration that a Chapter III registration is of no effect "shall be made in any case where an appeal has been preferred under section 17 and the decision of the district court has become final". It does not touch a decree of nullity of a marriage solemnized under Chapter II, or other matrimonial decrees.