The Hague Convention Abolishing the needed for Attestation (Legalization) for Foreign Certificates, the Apostille convention.
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The Apostille agreement is an International pact summarized by the Hague Conference on Private International Law. It specifies the modalities through which a document issued in one of the signatory Country can be certified for legal purposes in all the other signatory Country. Such a documentation is called an Apostille (It is a French word and it is Notary). It is an international documentation equivalent to a Notarization in Indian law.
OR
An apostille is a small certificate that authenticates the origin of commercial documents, personal, educational. Apostille can only be issued for documents issued in one country party to the Apostille convention and that are to be used in another country which is also a party to the convention. Apostille is an international attestation that is acceptable in above 107 countries.