Paragraph 5 makes provision as to how references to the subject matter of any enactment are to be construed.
Many reservations (or exceptions from reservations) in Schedule 5 are expressed by reference to the subject matter of particular enactments.  Paragraph 5(1) provides that references in Schedule 5 to enactments are to be read as references to that enactment as it has effect on the principal appointed day (1 July 1999) or, if it ceased to have effect at any time within the period ending with that day and beginning with the day on which the Scotland Act was passed (17 November 1999), as it had effect immediately before that time.  Accordingly, it does not matter if those enactments are amended or even repealed after that time: the references to them in the Schedule will continue to be read as they have effect on 1 July 1999.
“Principal appointed day” is defined in section 126(1) to mean the day which is designated as such in a commencement order under section 130.  This day is 1 July 1999 by virtue of S.I. 1998/3178.
Paragraph 5(1) is disapplied by Section C11 in Part II of Schedule 5, as amended by S.I. 2000/3252.  This is because it refers to the subject matter of the Postal Services Act 2000.  Instead that Section provides that this reference falls to be read by reference to the subject matter of that Act at the date when it received Royal Assent ( 28 July 2000).
Paragraph 5(2) provides for the making of transitional provision in relation to the operation of Schedule 5 at any time before 1 July 1999.
TABLE OF RESERVED MATTERS Detail of Provisions Paragraph 5: Interpretation