In all cases where by this Part, or under the authority thereof, or by virtue of any power or authority hereby given, a declaration--
(a) is substituted in lieu of an oath or affidavit, or
(b) is directed or authorised to be made and subscribed, although not substituted in lieu of an oath or affidavit,such declaration, unless otherwise directed by the powers hereby given, shall be in the form, or to the effect of the form, in either the Eighth or the Ninth Schedule.