The special administrative regions (SAR) of the People's Republic of China are one of the provincial-level autonomous administrative divisions of the People's Republic of China directly under the control of its Central People's Government (State Council), being integral areas of the country. As a region, they possess the highest degree of autonomy from China. However, despite the relative autonomy that the Central People's Government offers the special administrative regions, the National People's Congress remains capable of enforcing laws for the special administrative regions. The legal basis for the establishment of SARs, unlike the other administrative divisions of China, is provided for by Article 31, rather than Article 30, of the Constitution of the People's Republic of China of 1982. Article 31 reads: "The state may establish special administrative regions when necessary. The systems to be instituted in special administrative regions shall be prescribed by law enacted by the National People's Congress in the light of the specific conditions". At present, there are two SARs established according to the Constitution, namely the Hong Kong SAR and the Macau SAR, former British and Portuguese dependencies, respectively, transferred to China in 1997 and 1999, respectively, pursuant to the Sino-British Joint Declaration of 1984 and the Sino-Portuguese Joint Declaration of 1987. Pursuant to their Joint Declarations, which are binding inter-state treaties registered with the United Nations, and their Basic laws, the Chinese SARs "shall enjoy a high degree of autonomy". Generally, the two SARs are not considered to constitute a part of Mainland China, by both SAR and mainland Chinese authorities. The provision to establish special administrative regions appeared in the constitution in 1982, in anticipation of the talks with the United Kingdom over the question of the sovereignty over Hong Kong. It was envisioned as the model for the eventual unification with Taiwan and other islands, where the Republic of China has resided since 1949. Under the one country, two systems principle, the Chinese Central Government is responsible for the diplomatic, military and other state-level affairs of the two SARs. But two SARs continue to possess their own multi-party legislatures, legal systems, police forces, separate customs territory, immigration policies, left-hand traffic, official languages, academic and educational systems, representation on certain international bodies and representation in international competitions, and other aspects that falls within the autonomous level. Special administrative regions should not be confused with special economic zones, which are areas in which special