The United Kingdom has an uncodified constitution. The constitution consists of legislation, common law, Crown prerogative and constitutional conventions. Conventions may be written or unwritten. They are principles of behaviour which are not legally enforceable, but form part of the constitution by being enforced on a political, professional or personal level. Written conventions can be found in the Ministerial Code, Cabinet Manual, Guide to Judicial Conduct, Erskine May and even legislation. Unwritten conventions exist by virtue of long-practice or may be referenced in other documents such as the Lascelles Principles.