The Department of Foreign Affairs (DFA) performs its authentication functions in the context of the 1963 Vienna Convention on Consular Relations which allows for public documents, private documents, and commercial documents issued by a sovereign state, to have validity or operative effect in another sovereign state after it has undergone an agreed-upon authentication procedure.
The DFA, through the Authentication Division – Office of Consular Affairs, may authenticate an act, deed, document, etc. executed or sourced within the Philippines by certifying it. It attests to the genuineness of the signature appearing on the document for the purpose of identifying and giving credence to the official acts of the notary public or certifying officer on it for use, if and when required, as instrument of evidence in foreign countries.
After the due authentication of the documents by the DFA, the receiving Embassy, Consulate, or any other foreign legal entity is assured that these documents have been legalized in accordance with proper procedure.
To be clear, however, the DFA certification/authentication does not, per se, authenticate the validity/efficacy/enforceability of the document itself. The Authentication Officer then has the duty to exercise due carefulness and faithfulness and inform himself of the facts to which he intends to certify and avoid participation in illegal enterprises.