Convention on the Recognition and Enforcement of Foreign Arbitral Awards.
Done at New York on 10 June 1958.

The Convention, in principle, applies to all arbitral awards (Article I, paragraphs (1) and (2)).

However, Article I paragraph (3) allows states to make reservations:

When ... acceding to this Convention ... any State may on the basis of reciprocity declare that it will apply the Convention to the recognition and enforcement of awards made only in the territory of another Contracting State. It may also declare that it will apply the Convention only to differences arising out of legal relationships, whether contractual or not, which are considered as commercial under the national law of the State making such declaration.

1. States may limit the Convention to awards from other contracting states. Thus it is necessary to check whether both the state where enforcement is desired and the state where the award was "made" are both contracting states.
    
   Interestingly, the Convention also applies to the recognition of arbitration agreements (Article II) (requiring national courts to "refer the parties to arbitration"). The reservations of Article I though only apply to "recognition and enforcement of awards" [emphasis added].
    
    
2. States may limit the Convention to awards relating to commercial matters (see the exact wording above and/or in specific reservations made by states, e.g. "economic").
    
    
3. States may choose not to limit the Convention to only awards from other contracting states, but may however limit application to awards from non-contracting states such that they will only apply it to the extent to which such a non-contracting state grants reciprocal treatment. (See Article XIV.)
    
   (Whilst this in not the reciprocity reservation it is a reservation that is about reciprocal treatment. And, thus why "reciprocity" is not used as a description of either reservation on individual country pages.)