Definition of key terms

Accession: "Accession" is the act whereby a state accepts the offer or the opportunity to become a party to a treaty already negotiated and signed by other states. It has the same legal effect as ratification. Accession usually occurs after the treaty has entered into force. The Secretary-General of the United Nations, in his function as depository, has also accepted accessions to some conventions before their entry into force. The conditions under which accession may occur and the procedure involved depend on the provisions of the treaty. A treaty might provide for the accession of all other states or for a limited and defined number of states. In the absence of such a provision, accession can only occur where the negotiating states were agreed or subsequently agree on it in the case of the state in question. [See Arts.2 (1) (b) and 15, Vienna Convention on the Law of Treaties 1969]

Adoption: "Adoption" is the formal act by which the form and content of a proposed treaty text are established. As a general rule, the adoption of the text of a treaty takes place through the expression of the consent of the states participating in the treaty-making process. Treaties that are negotiated within an international organization will usually be adopted by a resolution of a representative organ of the organization whose membership more or less corresponds to the potential participation in the treaty in question. A treaty can also be adopted by an international conference which has specifically been convened for setting up the treaty, by a vote of two thirds of the states present and voting, unless, by the same majority, they have decided to apply a different rule. [See Art.9, Vienna Convention of the Law of Treaties 1969]

Charters: The term "charter" is used for particularly formal and solemn instruments, such as the constituent treaty of an international organization. The Charter of the United Nations of 1945 is a good example.

Conventions: The generic term "convention" is synonymous with the generic term "treaty". Conventions are normally open for participation by the international community as a whole, or by a large number of states. Usually the instruments negotiated under the auspices of an international organization are entitled conventions (e.g. the 1989 Convention on the Rights of the Child, adopted by the General Assembly of the UN).

Declarations: The term "declaration" is used for various international instruments. However, declarations are not always legally binding. The term is often deliberately chosen to indicate that the parties do not intend to create binding obligations but merely want to declare certain aspirations.  Declarations can however also be treaties in the generic sense intended to be binding at international law. It is therefore necessary to establish in each individual case whether the parties intended to create binding obligations. Ascertaining the intention of the parties can often be a difficult task. Some instruments entitled "declarations" were not originally intended to have binding force, but their provisions may have reflected customary international law or may have gained binding character as customary law at a later stage. Such was the case with the 1948 Universal Declaration of Human Rights.

Deposit: After a treaty has been concluded, the written instruments, which provide formal evidence of consent to be bound, and also reservations and declarations, are placed in the custody of a depository. Unless the treaty provides otherwise, the deposit of the instruments of ratification, acceptance, approval or accession establishes the consent of a state to be bound by the treaty. For treaties with a small number of parties, the depository will usually be the government of the state on whose territory the treaty was signed. Sometimes various states are chosen as depositories. Multilateral treaties usually designate an international organization or the Secretary-General of the United Nations as depositories. The depository must accept all notifications and documents related to the treaty, examine whether all formal requirements are met, deposit them, register the treaty and notify all relevant acts to the parties concerned. [See Arts.16, 76 and 77, Vienna Convention on the Law of Treaties 1969]

Entry into Force: Typically, the provisions of the treaty determine the date on which the treaty enters into force. Where the treaty does not specify a date, there is a presumption that the treaty is intended to come into force as soon as all the negotiating states have consented to be bound by the treaty. Bilateral treaties may provide for their entry into force on a particular date, upon the day of their last signature, upon exchange of the instruments of ratification or upon the exchange of notifications. In cases where multilateral treaties are involved, it is common to provide for a fixed number of states to express their consent for entry into force. Some treaties provide for additional conditions to be satisfied, e.g., by specifying that a certain category of states must be among the consenters. The treaty may also provide for an additional time period to elapse after the required number of countries have expressed their consent or the conditions have been satisfied. A treaty enters into force for those states which gave the required consent. A treaty may also provide that, upon certain conditions having been met, it shall come into force provisionally. [See Art.24, Vienna Convention on the Law of Treaties 1969]

Protocols: The term "protocol" is used for agreements less formal than those entitled "treaty" or "convention". The term can be used to cover an Optional Protocol to a Treaty, which is an instrument that establishes additional rights and obligations to a treaty. An Optional Protocol is of independent character and subject to independent ratification. Such protocols enable certain parties of the treaty to establish among themselves a framework of obligations which reach further than the general treaty and to which not all parties of the general treaty consent.

Ratification: Ratification defines the international act whereby a state indicates its consent to be bound to a treaty if the parties intended to show their consent by such an act. In the case of bilateral treaties, ratification is usually accomplished by exchanging the requisite instruments, while in the case of multilateral treaties the usual procedure is for the depository to collect the ratifications of all states, keeping all parties informed of the situation. The institution of ratification grants states the necessary time-frame to seek the required approval for the treaty on the domestic level and to enact the necessary legislation to give domestic effect to that treaty. [See Arts.2 (1) (b), 14 (1) and 16, Vienna Convention on the Law of Treaties 1969]

Signature Subject to Ratification, Acceptance or Approval: Where the signature is subject to ratification, acceptance or approval, the signature does not establish the consent to be bound. However, it is a means of authentication and expresses the willingness of the signatory state to continue the treaty-making process. The signature qualifies the signatory state to proceed to ratification, acceptance or approval. It also creates an obligation to refrain, in good faith, from acts that would defeat the object and the purpose of the treaty. [See Arts. 10 and 18, Vienna Convention on the Law of Treaties 1969]

Treaties: The term "treaty" is used generically to refer to instruments binding at international law, concluded between international entities, regardless of their formal designation. The 1969 Vienna Convention defines a treaty as "an international agreement concluded between States in written form and governed by international law, whether embodied in a single instrument or in two or more related instruments and whatever its particular designation". The 1986 Vienna Convention extends the definition of treaties to include international agreements involving international organizations as parties. In order to speak of a "treaty" in the generic sense, an instrument has to meet various criteria. First of all, it has to be a binding instrument, which means that the contracting parties intended to create legal rights and duties. Secondly, the instrument must be concluded by states or international organizations with treaty-making power. Thirdly, it has to be governed by international law. Finally the engagement has to be in writing.

Source: United Nations Treaty Collection, Treaty Reference Guide (1999), available at




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