Article 25: Reservations

1. At the time of signature, ratification, acceptance, approval or accession, each State may formulate reservations, unless the reservations are incompatible with the object and purpose of this Treaty.

2. A State Party may withdraw its reservation at any time by notification to this effect addressed to the Depositary.

[A] unilateral statement, however phrased or named, made by a State or an international organization when signing, ratifying, formally confirming, accepting, approving or acceding to a treaty, or by a State when making a notification of succession to a treaty, whereby the State or organization purports to exclude or to modify the legal effect of certain provisions of the treaty in their application to that State or to that international organization (ILC Guide, 2011, 1.1).

[T]here are probably few subjects in classical general international law which ignite such impassioned debates as the apparently extremely technical subject of reservations to treaties [ … ]: for some, reservations are an absolute evil because they cause injury to the integrity of the treaty; for others, to the contrary, they facilitate a broader adhesion and, thus, universality (Pellet, 2013, p. 323).