Twenty-second Amendment to the United States Constitution
Some argue that the 22nd Amendment and 12th Amendment bar any two-term president from later serving as vice president as well as from succeeding to the presidency from any point in the presidential line of succession. Others contend that the original intent of the 12th Amendment concerns qualification for "service" (age, residence, and citizenship), while the 22nd Amendment, concerns qualifications for "election", and thus (strictly applying the text) a former two-term president is still eligible to "serve" as vice president (neither amendment restricts the number of times an individual can be elected to the vice presidency), and then succeed to the presidency to serve out the balance of the term (though prohibited from running for election to an additional term).
Constitution of the United Kingdom
There are many Acts of Parliament which themselves have constitutional significance. For example, Parliament has the power to determine the length of its term. By the Parliament Acts 1911 and 1949, the maximum length of a term of parliament is five years but this may be extended with the consent of both Houses. This power was most recently used during World War II to extend the lifetime of the 1935 parliament in annual increments up to 1945. Parliament also has the power to change the make-up of its constituent houses and the relation between them. Examples include the House of Lords Act 1999 which changed the membership of the House of Lords, the Parliament Acts 1911 and 1949 which altered the relationship between the House of Commons and the House of Lords, and the Reform Act 1832 which made changes to the system used to elect members of the House of Commons.