For example, the short title of the House of Lords Act 1999 is House of Lords Act 1999, but its long title is An Act to restrict membership of the House of Lords by virtue of a hereditary peerage; to make related provision about disqualifications for voting at elections to, and for membership of, the House of Commons; and for connected purposes.
Like other descriptive components of an act (such as the preamble, section headings, side notes, and short title), the long title seldom affects the operative provisions of an Act, except where the operative provisions are unclear or ambiguous and the long title provides a clear statement of Parliament's intention.
The long title is important since, under the procedures of Parliament, a Bill cannot be amended to go outside the scope of its long title. For that reason, the long title tends to be rather vague, ending with the formulation "and for connected purposes".
Many early Acts were enacted without a short title, and the long title was used to identify the Act, although short titles were given to many of the extant Acts at later dates. The Bill of Rights was given that short title by the Short Titles Act 1896; previously, it was formally known by its long title, An Act Declaring the Rights and Liberties of the Subject and Settling the Succession of the Crown. The long title for older Acts is sometimes termed its rubric because it was sometimes printed in red.
The long title should be distinguished from the preamble, which is an optional part of an Act or Bill and follows immediately after the long title and date of Royal Assent, consisting of a number of preliminary statements of facts similar to recitals, each starting Whereas....