word | | Constitution |
| April | Pakistan | 12 April 1973; suspended 5 July 1977, restored 30 December 1985; suspended 15 October 1999, restored in stages in 2002; amended 31 December 2003; suspended 3 November 2007; restored 15 December 2007 ... |
| April | Poland | adopted by the National Assembly 2 April 1997; passed by national referendum 25 May 1997; effective 17 October 1997 |
| April | Portugal | adopted 2 April 1976; subsequently revised note: the revisions placed the military under strict civilian control, trimmed the powers of the president, and laid the groundwork for a stable, pluralistic liberal democracy ... |
| April | Qatar | ratified by public referendum 29 April 2003; endorsed by the Amir 8 June 2004, effective 9 June 2005 |
| April | Switzerland | revision of Constitution of 1874 approved by the Federal Parliament 18 December 1998, adopted by referendum 18 April 1999, officially entered into force 1 January 2000 |
| April | Tanzania | 25 April 1977; major revisions October 1984 |
| April | Vietnam | 15 April 1992 |
| Areas | Akrotiri | Sovereign Base Areas of Akrotiri and Dhekelia Order in Council 1960, effective 16 August 1960, functions as a basic legal document |
| Areas | Dhekelia | Sovereign Base Areas of Akrotiri and Dhekelia Order in Council 1960, effective 16 August 1960, functions as a basic legal document |
| Article | European Union | ... in nature; the Treaty on European Union (TEU), as modified by the Lisbon Treaty, states in Article 1 that "the HIGH CONTRACTING PARTIES establish among themselves a EUROPEAN UNION ... on which the ... |
| articles | Haiti | approved March 1987 note: suspended June 1988 with most articles reinstated March 1989; constitutional government ousted in a military coup in September 1991, although in October 1991 military government claimed to be ... |
| articulates | Saudi Arabia | governed according to Islamic law; the Basic Law that articulates the government's rights and responsibilities was promulgated by royal decree in 1992 |
| Ascension | Saint Helena | The Saint Helena, Ascension and Tristan da Cunha Constitution Order 2009, effective 1 September 2009 |