Employment Court, the Environment Court and the Māori Land Court, as well as the Family Court and the Youth Court, which operate as specialised divisions of the District Courts. There are also a number of specialised tribunals which operate in a judicial or quasi-judicial capacity, such as the Disputes Tribunal, the Tenancy Tribunal and the Waitangi Tribunal. Law New Zealand law has three principal sources: English common law; certain statutes of the United Kingdom Parliament enacted before 1947 (notably the Bill of Rights 1689); and statutes of the New Zealand Parliament. In interpreting common law, there is a rebuttable presumption in support of uniformity with common law as interpreted in the United Kingdom and related jurisdictions. Non-uniformity arises where the New Zealand courts consider local conditions to warrant it or where the law has been codified by New Zealand statute. The maintenance of the Judicial Committee of the Privy Council in London as the final court of appeal and judges' practice of tending to follow British decisions, even though, technically, they are not bound by them, both bolstered this presumption. The Supreme Court of New Zealand, which was established by legislation in October 2003 and which replaced the Privy Council for future appeals, has continued to develop the presumption. Judgment was delivered on 3 March 2015 in the last appeal from New Zealand to be heard by the Privy Council. Treaty of Waitangi The place of the Treaty of Waitangi in the constitution is the subject of much debate. The Treaty has no inherent legal status, but is treated in various statutes and is increasingly seen as an important source of constitutional law. The Treaty of Waitangi Act 1975 put the text of the Treaty in statute for the first time (as a schedule) and created the Waitangi Tribunal to investigate claims relating to the application of the principles of the Treaty. The Act was initially prospective but was amended in 1985 so that claims dating back to the signing of the Treaty in 1840 could be investigated. References to the "principles of the Treaty of Waitangi" appear in a number of statutes, although the principles themselves have not been defined in statute. They are instead defined by a common law decision of the Court of Appeal from 1987, the famous "Lands case" brought by the New Zealand Māori Council (New Zealand Maori Council v Attorney-General) over concerns about the