The ruling on the South China Sea dispute has had critics questioning the authority of the tribunal, its source of legitimacy and the strength of its ruling. East Asia Editor Goh Sui Noi examines the processes that led to the findings and legal standing of the arbitration panel.

Q How did the Philippines start the arbitration process?

A The Philippines started the arbitration process against China on Jan 23, 2013, by issuing a Notification and Statement of Claim to the Chinese, in accordance with the dispute settlement provisions of the United Nations Convention on the Law of the Sea (Unclos).

China formally rejected the Notification and Statement of Claim, returning it to the Philippines on Feb 19, 2013. However, under Unclos, the refusal of one party to participate in the arbitration process does not bar it from proceeding.

As neither side has made known which of the four dispute settlement procedures under Unclos it would like to use, it is deemed that they have chosen arbitration by an arbitral tribunal constituted in accordance with Annex VII of Unclos.

The other three are the International Tribunal for the Law of the Sea (Itlos), the International Court of Justice and a special arbitral tribunal constituted in accordance with Annex VIII.

Q What is the five-man arbitral tribunal and what powers does it have?

A Parties to the case choose their arbitrators from a list of arbitrators that is maintained by the secretary-general of the United Nations. Each side picks one arbitrator and the other three are appointed by agreement between the two sides.

As China had decided not to participate in the case, the president of Itlos appointed China's arbitrator on its behalf. Itlos' president also appointed the other three arbitrators.

The tribunal determines its own procedure, with each party given full opportunity to be heard and to present its case. Decision is taken by a majority vote of the tribunal's members, and the award is final and binding and without appeal. It should be complied with by the parties to the dispute.

The expenses of the tribunal, including the remuneration of its members, are borne equally by the parties to the dispute. In this case, as China did not take part in it, the Philippines has paid its and China's shares of the expenses so far, leading the Chinese to question the credibility of the tribunal.

China has also insisted that the tribunal has no jurisdiction over the case as it involves sovereignty over islands in the South China Sea. But the tribunal in its first award in October last year said it had jurisdiction as matters submitted by the Philippines did not concern sovereignty but reflected a dispute that concerns Unclos.

Q What is Unclos?

A Unclos is a treaty concluded in 1982 that came into force in 1994. Ratified by 168 parties, including the Philippines and China, it establishes a legal order for the seas and oceans that promotes the peaceful use of the oceans and facilitates international communication.

It establishes rules for allocating and managing natural resources of the oceans and rules for protection and preservation of the marine environment.

An integral part of Unclos is the dispute settlement regime and when a party signs up to Unclos, it agrees in advance to the system of compulsory dispute settlement that can result in a final and binding decision.

Q What is the Permanent Court of Arbitration?

A The Permanent Court of Arbitration (PCA) is an inter-governmental organisation in The Hague that facilitates arbitration and other forms of dispute resolution between states.

In this arbitration case, it acts as a registry for the arbitral tribunal and provides administrative support to the tribunal.

While there have been frequent, loosely phrased references to the ruling as emanating from the PCA, strictly speaking the arbitration tribunal derives its authority from a body of international laws sanctioned by the UN.

Q Critics say the ruling is rubbish because it touches on sovereignty. Is this the case?

A This case is not about sovereignty but about maritime rights under Unclos. The tribunal did not rule on sovereignty.

In the case of China's claims to historic rights within the nine-dash line, such rights were extinguished when it ratified Unclos if those waters are now within the 200 nautical mile, exclusive economic zones (EEZs) of other coastal states.

Under Unclos, coastal states have rights to explore and exploit all living and non-living resources in their EEZs.

The tribunal also ruled on the status and entitlement of the reefs occupied by China, including whether they were entitled to a territorial sea or an EEZ.

Q Is the ruling invalid because Manila violated the DOC?

A The tribunal established in its October 2015 award that the 2002 China-Asean Declaration on the Conduct of Parties in the South China Sea (DOC) "is a political agreement and not legally binding, does not provide a mechanism for binding settlement, and does not exclude other means of settlement". It came to the same conclusion with regards to joint statements of China and the Philippines on resolving their disputes through negotiation.

China in its argument that the ruling is null and void gave as one of the reasons that the Philippines had violated the standing agreement between the two countries to resolve disputes through bilateral negotiations - as found in the 2002 China-Asean Declaration on the Conduct of Parties in the South China Sea and in their bilateral documents.

Q Is the ruling enforceable?

A The ruling is not enforceable because Unclos does not have an enforcement mechanism. Some analysts have pointed out that studies have shown that the vast majority of decisions by international courts and tribunals are implemented. However, others have said that where a ruling infringed on a great power's sovereignty or national security interests, it has never been accepted or complied with.