773.Subsection (1) ensures that, where another enactment is applied by the Act or by subordinate legislation made under it, for this purpose the applied enactment extends to (i.e. forms part of the law of) every part of the UK, even if the original enactment extends only to part of the UK.
774.Subsection (2) similarly applies the rules in section 384 (which deals with the extent of the Act outside the UK) to any enactment applied by or under the Act.