In certain jurisdictions, including the United Kingdom and other Westminster-influenced jurisdictions (such as Canada or Australia), as well as the United States and the Philippines, primary legislation has both a short title and a long title.
The long title (properly, the title in some jurisdictions) is the formal title appearing at the head of a statute (such as an act of Parliament or of Congress) or other legislative instrument. The long title is intended to provide a summarised description of the purpose or scope of the instrument. 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 the legislature's intention.
The short title is the formal name by which legislation may by law be cited. It contrasts with the long title which, while usually being more fully descriptive of the legislation's purpose and effects, is generally too unwieldy for most uses. For example, the short title House of Lords Act 1999 contrasts with the long title 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.