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.