In recognition of the government's sovereignty claim over the South China Sea and in order to draw citizens' attention to the government's policy concerning such, this Directorate issued a set of two stamps featuring the landscape of the Pratas and Itu Aba Island as well as the monument built on these islands by the Ministry of Interior. It also issued a souvenir sheet with a map of South China Sea in the background.　　The South China Sea is actually a collective term for many islands dotting the huge waters between Mainland China, the Philippines, Indochina, Borneo, and Sumatra. In terms of geographical location, in the eastern part of the sea are the Pratas Islands; in the west, the Paracel Islands; in the south, the Spratly Islands, and in the middle, the Macclesfield Bank. According to many past and present historical and geographical books, these four Island groups have-been Chinese territory as early as the Chin dynasty. For years they have served as a base for Taiwanese deep sea fishing boats. Because of the strategic location and huge amount of gas and petroleum potential, these four islands are coveted by many neighboring countries. In the wake of the passing of UNCLOS (United Nations Convention On The Law Of The Sea) which proclaims a nation's territorial sea to be 12 nautical miles, its contiguous zone to be 24 nautical miles, and its exclusive economic zone to be 200 nautical miles, countries like the Philippines, Vietnam, and Malaysia have even gone so far as to actually occupy parts of the Spratly Islands, thinking they could benefit from the 200 nautical miles of exclusive economic zone by owning some of the islands in South China Sea.