The New Zealand constitution: Its main features The New Zealand constitution is to be found in formal legal documents, in decisions of the courts, and in practices (some of which are described as conventions). It reflects and establishes that New Zealand is a monarchy, that it has a parliamentary system of government, and that it is a democracy. It increasingly reflects the fact that the Treaty of Waitangi is regarded as a founding document of government in New Zealand. The constitution must also be seen in its international context, because New Zealand governmental institutions must increasingly have regard to international obligations and standards