2(1)An Act of the Scottish Parliament cannot modify, or confer power by subordinate legislation to modify, the law on reserved matters.
(2)In this paragraph, “the law on reserved matters” means—
(a)any enactment the subject-matter of which is a reserved matter and which is comprised in an Act of Parliament or subordinate legislation under an Act of Parliament, and
(b)any rule of law which is not contained in an enactment and the subject-matter of which is a reserved matter,
and in this sub-paragraph “Act of Parliament” does not include this Act.
(3)Sub-paragraph (1) applies in relation to a rule of Scots private law or Scots criminal law (whether or not contained in an enactment) only to the extent that the rule in question is special to a reserved matter or the subject-matter of the rule is—
(a)interest on sums due in respect of taxes or excise duties and refunds of such taxes or duties, or
(b)the obligations, in relation to occupational or personal pension schemes, of the trustees or managers.
(4)Sub-paragraph (3)(b) extends to cases where liabilities under orders made in matrimonial proceedings, or agreements made between the parties to a marriage, are to be satisfied out of assets of the scheme.
3(1)Paragraph 2 does not apply to modifications which—
(a)are incidental to, or consequential on, provision made (whether by virtue of the Act in question or another enactment) which does not relate to reserved matters, and
(b)do not have a greater effect on reserved matters than is necessary to give effect to the purpose of the provision.
(2)In determining for the purposes of sub-paragraph (1)(b) what is necessary to give effect to the purpose of a provision, any power to make laws other than the power of the Parliament is to be disregarded.