Glossary of terms relating to Treaty actions
This glossary is intended as a general guide and is not presumed to be exhaustive
Acceptance or Approval
Act of Formal Confirmation
Correction of Errors
Entry into Force
Exchange of Letters/Notes
Registration and Publication
Signature ad referendum
Signature Subject to Ratification, Acceptance or Approval
"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.
[Art.9, Vienna Convention of the Law of Treaties 1969]
2. Acceptance and Approval
The instruments of "acceptance" or "approval" of a treaty have the same legal effect as
ratification and consequently express the consent of a state to be bound by a treaty. In the practice
of certain states acceptance and approval have been used instead of ratification when, at a national
level, constitutional law does not require the treaty to be ratified by the head of state.
[Arts.2 (1) (b) and 14 (2), Vienna Convention on the Law of Treaties 1969]
"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 depositary, 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
[Arts.2 (1) (b) and 15, Vienna Convention on the Law of Treaties 1969]
4. Act of Formal Confirmation
"Act of formal confirmation" is used as an equivalent for the term "ratification" when an
international organization expresses its consent to be bound to a treaty.
[Arts.2 (1) (b bis) and 14, Vienna Convention on the Law of Treaties between States and
International Organizations or between International Organizations 1986]
The term "amendment" refers to the formal alteration of treaty provisions affecting all the
parties to the particular agreement. Such alterations must be effected with the same formalities that
attended the original formation of the treaty. Many multilateral treaties lay down specific
requirements to be satisfied for amendments to be adopted. In the absence of such provisions,
amendments require the consent of all the parties.
[Art.40, Vienna Convention of the Law of Treaties 1969]
The term "authentication" refers to the procedure whereby the text of a treaty is established
as authentic and definitive. Once a treaty has been authenticated, states cannot unilaterally change
its provisions. If states which negotiated a given treaty do not agree on specific procedures for
authentication, a treaty will usually be authenticated by signature, signature ad referendum or the
initialling by the representatives of those states.
[Art.10, Vienna Convention on the Law of Treaties 1969]
7. Correction of Errors
If, after the authentication of a text, the signatory and contracting states are agreed that it
contains an error, it can be corrected by initialling the corrected treaty text, by executing or
exchanging an instrument containing the correction or by executing the corrected text of the whole
treaty by the same procedure as in the case of the original text. If there is a depositary, the depositary
must communicate the proposed corrections to all signatory and contracting states. In the UN
practice, the Secretary-General, in his function as depositary, informs all parties to a treaty of the
errors and the proposal to correct it. If, on the expiry of an appropriate time-limit, no objections are
raised by the signatory and contracting states, the depositary circulates a proces-verbal of
rectification and causes the corrections to be effected in the authentic text(s).
[Art.79, Vienna Convention on the Law of Treaties 1969]
Sometimes states make "declarations" as to their understanding of some matter or as to the
interpretation of a particular provision. Unlike reservations, declarations merely clarify the state's
position and do not purport to exclude or modify the legal effect of a treaty. Usually, declarations
are made at the time of the deposit of the corresponding instrument or at the time of signature.
9. Definitive Signature
When the treaty is not subject to ratification, acceptance or approval, "definitive signature"
establishes the consent of the state to be bound by the treaty. Most bilateral treaties dealing with
more routine and less politicized matters are brought into force by definitive signature, without
recourse to the procedure of ratification.
[Art.12, Vienna Convention on the Law of Treaties 1969]
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
depositary. 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 depositary will usually be the government of the state
on whose territory the treaty was signed. Sometimes various states are chosen as depositaries.
Multilateral treaties usually designate an international organization or the Secretary-General of the
United Nations as depositaries. The depositary 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.
[Arts.16, 76 and 77, Vienna Convention on the Law of Treaties 1969]
11. 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.
[Art.24, Vienna Convention on the Law of Treaties 1969]
12. Exchange of Letters/Notes
States may express their consent to be bound by an "exchange of letters/notes". The basic
characteristic of this procedure is that the signatures do appear not on one letter or note but on two
separate letters or notes. The agreement therefore lies in the exchange of both letters or notes, each
of the parties having in their possession one letter or note signed by the representative of the other
party. In practice, the second letter or note, usually the letter or note in response, will typically
reproduce the text of the first. In a bilateral treaty, letters or notes may also be exchanged to indicate
that all necessary domestic procedures have been completed.
[Art.13, Vienna Convention on the Law of Treaties 1969]
13. Full Powers
"Full powers" means a document emanating from the competent authority of a state
designating a person or persons to represent the state for negotiating, adopting, authenticating the
text of a treaty, expressing the consent of a state to be bound by a treaty, or for accomplishing any
other act with respect to that treaty. Heads of State, Heads of Government and Ministers for Foreign
Affairs are considered as representing their state for the purpose of all acts relating to the conclusion
of a treaty and do not need to present full powers. Heads of diplomatic missions do not need to
present full powers for the purpose of adopting the text of a treaty between the accrediting state and
the state to which they are accredited. Likewise, representatives accredited by states to an
international conference or to an international organization or one of its organs do not need to
present full powers for the purpose of adopting the text of a treaty in that conference, organization
[Art.2 (1) (c) and Art.7 Vienna Convention on the Law of Treaties 1969]
The term "modification" refers to the variation of certain treaty provisions only as between
particular parties of a treaty, while in their relation to the other parties the original treaty provisions
remain applicable. If the treaty is silent on modifications, they are allowed only if the modifications
do not affect the rights or obligations of the other parties to the treaty and do not contravene the
object and the purpose of the treaty.
[Art.41, Vienna Convention on the Law of Treaties 1969]
The term "notification" refers to a formality through which a state or an international
organization communicates certain facts or events of legal importance. Notification is increasingly
resorted to as a means of expressing final consent. Instead of opting for the exchange of documents
or deposit, states may be content to notify their consent to the other party or to the depositary.
However, all other acts and instruments relating to the life of a treaty may also call for notifications.
[Arts.16 (c), 78 etc,. Vienna Convention on the Law of Treaties 1969]
Any signatory or contracting state has the option of objecting to a reservation, inter alia, if,
in its opinion, the reservation is incompatible with the object and purpose of the treaty. The
objecting state may further declare that its objection has the effect of precluding the entry into force
of the treaty as between objecting and reserving states.
[Art.20-23, Vienna Convention on the Law of Treaties 1969]
Application and Provisional Entry into Force of Treaties
1. Provisional Application
The growing use of provisional application clauses in treaties is a
consequence of the need felt to give effect to treaty obligations prior to a
state?s formal ratification of/accession to a treaty. The obligations relating
to provisional application are undertaken by a conscious voluntary act of the
state consistent with its domestic legal framework.
Provisional application of a treaty that has entered into force
The provisional application of a treaty that has entered into force may
occur when a state undertakes to give effect to the treaty obligations
provisionally although its domestic procedures for ratification/accession have
not yet been completed. The intention of the state would be to ratify/accede to
the treaty once its domestic legal requirements have been met. Provisional
application may be terminated at any time. In contrast, a state which has
consented to be bound by a treaty through ratification/accession or definitive
signature, is governed by the rules on withdrawal specified in the treaty
concerned (Arts. 54, 56, Vienna Convention on the Law of Treaties 1969).
[Art. 25, Vienna Convention on the Law of Treaties 1969]
Provisional application of a treaty that has not entered into force
Provisional application of a treaty that has not entered into force may
occur when a state notifies that it would give effect to the legal obligations
specified in that treaty provisionally. These legal obligations are
undertaken by a conscious voluntary act of the state consistent with its
domestic legal framework. Provisional application may be terminated at any time.
In contrast, a state which has consented to be bound by a treaty through
ratification/ accession or definitive signature, is governed by the rules on
withdrawal specified in the treaty concerned (Arts. 54, 56, Vienna Convention on
the Law of Treaties 1969).
Provisional application may continue even after the entry into force of the
treaty in relation to a state applying the treaty provisionally until that state
has ratified it. Provisional application terminates if a state notifies the
other states among which the treaty is being applied provisionally of its
intention of not becoming a party to the treaty.
[Art. 25 (2), Vienna Convention on the Law of Treaties 1969]
2. Provisional Entry into Force
There are also an increasing number of treaties which include provisions for provisional
entry into force. Such treaties provide mechanisms for entry into force
provisionally, should the formal criteria for entry into force not be met within
a given period. Provisional entry into force of a treaty may also occur when a
number of parties to a treaty which has not yet entered into force, decide to
apply the treaty as if it had entered into force. Once a Treaty has entered into
force provisionally, it is binding on the parties which agreed to bring it into
The nature of the legal obligations resulting from provisional entry into
force would appear to be the same as the legal obligations in a treaty that has
entered into force, as any other result would create an uncertain legal
situation. It is the criteria for formal entry into force that have not been met
but the legal standard of the obligations remains.
[Art. 25 (1), Vienna Convention on the Law of Treaties 1969]
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 depositary 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.
[Arts.2 (1) (b), 14 (1) and 16, Vienna Convention on the Law of Treaties 1969]
19. Registration and Publication
Article 102 of the Charter of the United Nations provides that "every treaty and every
international agreement entered into by any Member of the United Nations after the present Charter
comes into force shall as soon as possible be registered with the Secretariat and published by it".
Treaties or agreements that are not registered cannot be invoked before any organ of the United
Nations. Registration promotes transparency and the availability of texts of treaties to the public.
Article 102 of the Charter and its predecessor, Article 18 of the Pact of the League of Nations, have
their origin in one of Woodrow Wilson's Fourteen Points in which he outlined his idea of the League
of Nations: "Open covenants of peace, openly arrived at, after which there shall be no private
international understandings of any kind but diplomacy shall proceed always openly and in the
[Art.80, Vienna Convention on the Law of Treaties 1969]
A reservation is a declaration made by a state by which it purports to exclude or alter the
legal effect of certain provisions of the treaty in their application to that state. A reservation enables
a state to accept a multilateral treaty as a whole by giving it the possibility not to apply certain
provisions with which it does not want to comply. Reservations can be made when the treaty is
signed, ratified, accepted, approved or acceded to. Reservations must not be incompatible with the
object and the purpose of the treaty. Furthermore, a treaty might prohibit reservations or only allow
for certain reservations to be made.
[Arts.2 (1) (d) and 19-23, Vienna Convention of the Law of Treaties 1969]
Revision has basically the same meaning as amendment. However, some treaties provide
for a revision additional to an amendment (i.e., Article 109 of the Charter of the United Nations).
In that case, the term "revision" refers to an overriding adoption of the treaty to changed
circumstances, whereas the term "amendment" refers only to a change of singular provisions.
22. Signature ad referendum
A representative may sign a treaty "ad referendum", i.e., under the condition that the
signature is confirmed by his state. In this case, the signature becomes definitive once it is confirmed
by the responsible organ.
[Art.12 (2) (b), Vienna Convention on the Law of Treaties 1969]
23. 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.
[Arts.10 and 18, Vienna Convention on the Law of Treaties 1969]