(1) Section 17 (as amended by the Finance Act, 1992) of the Finance Act, 1970, is hereby amended -
(a) in subsection (1), by the substitution of the following definition for the definition of "certification of authorisation":
"'certificate of authorisation' means a certificate issued under subsection (7), which certificate shall be valid for such period as the Revenue Commissioners may by regulations made in accordance with subsection (5) provide;",
(b) in subsection (5) -
(i) by the insertion of the following paragraph after paragraph (a):
(i) the making, before the entering into of a relevant contract, by the persons who intend to enter into such a contract of a declaration, in a specified form, to the effect that, having regard to guidelines published by the Revenue Commissioners for the information of such persons as to the distinctions between contracts of employment and relevant contracts and without prejudice to the question of whether a particular contract is a contr