This is one of a set of provisions defining the legislative competence of the Scottish Parliament.  Section 28 provides for the Parliament to make laws known as Acts of the Scottish Parliament (ASPs).  Section 29 defines the legislative competence of the Parliament.  Section 30 introduces the list of reserved matters (which are set out in Schedule 5) and provides for the modification of Schedules 4 and 5 by subordinate legislation, subject to the approval of both the Scottish Parliament and the UK Parliament.
Section 53 provides for the transfer to the Scottish Ministers of most types of Ministerial function which are exercisable within devolved competence.  “Devolved competence” is defined in section 54.  Essentially, a function is exercisable within devolved competence if it could have been conferred by an Act of the Scottish Parliament.  Part III of the present Schedule modifies sections 53 and 54 in relation to those enactments and other aspects of the law which are protected from modification by Parts I and II.  Its effect is that, in general, Ministerial functions under such enactments or law are not transferred.  However, there are certain exceptions to this.
General