The first use of the term "West Philippine Sea" by the Philippine government was as early as 2011 during the administration of then-President Benigno Aquino III. The naming was intended as symbolic gesture to dispute the China's sovereignty claim over the whole South China Sea. In September 2012, the Philippine government announced that it would start using the name to refer to waters west of the Philippines as "West Philippine Sea" in government maps, other forms of communication and documents.
2016 PCA ruling
On July 12, 2016, the Permanent Court of Arbitration ruled in favor of the Philippines. It clarified that it would not "...rule on any question of sovereignty over land territory and would not delimit any maritime boundary between the Parties". The tribunal also ruled that China has "no historical rights" based on the "nine-dash line" map.
Legal scope
In Philippine law, the West Philippine Sea refers to only portions of the South China Sea particularly parts of the sea which the Philippine government claims to be part of the country's exclusive economic zone. The naming of the area became official through Administrative Order No. 29 issued by then-President Benigno Aquino III on September 5, 2012. The order also cites Presidential Decree No. 1599 which was issued in 1978 during the tenure of then President Ferdinand Marcos which established the Philippine EEZ as well as the Republic Act No. 9522 or the Baselines Law which was enacted into law in 2009 during the administration of then-President Gloria Macapagal Arroyo which delineated the baselines of the Philippine archipelago. The administrative order asserts the Philippine claim over its EEZ in the South China Sea which conveys the Philippine government's position that it has sovereign rights under the 1982 United Nations Convention on the Law of the Sea over the West Philippine Sea area and "inherent power and right to designate its maritime areas with appropriate nomenclature for purposes of the national mapping system". There is no exact demarcation for the area in the South China Sea which forms the West Philippine Sea.
Usage
Under the Administrative Order No. 29, the National Mapping and Resource Information Authority is mandated to use the designation West Philippine Sea in maps produced and published by the government agency. Other government agencies are also required to use the term to popularize the use of the name domestically and internationally. Prior to the issuance of the order, the Philippines' weather bureau, PAGASA, adopted the name in 2011 to refer to waters west of the country while remained using "Philippine Sea" to refer waters east of the archipelago.
