A collective title is an expression by which two or more pieces of legislation may, under the law of the United Kingdom, be cited together. A famous example is the Parliament Acts 1911 and 1949.
Effect of repeal
Section 19(2) of the Interpretation Act 1978 does not authorise the continued use of a collective title previously authorised by a repealed enactment.
References
Collective title Wikipedia(Text) CC BY-SA