Twenty-second Amendment to the United States Constitution
As worded, the primary focus of the 22nd Amendment is on limiting individuals twice elected to the presidency from being elected again. Due to this, several issues could be raised regarding the amendment's meaning and application, especially in relation to the 12th Amendment, ratified in 1804, which states, "But no person constitutionally ineligible to the office of President shall be eligible to that of Vice-President of the United States". While it is clear that under the 12th Amendment the original constitutional qualifications of age, citizenship, and residency apply to both the president and vice president, it is unclear whether someone who is ineligible to be elected president could be elected vice president. Because of this apparent ambiguity, there may be a loophole in the 22nd Amendment whereby a two-term former-president could be elected vice president and then succeed to the presidency as a result of the incumbent's death, resignation, or removal from office (or even succeed to the presidency from some other stated office in the presidential line of succession).
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.