Vienna Convention on the Law of Treaties between States and International Organizations

SECTION 2.
RESERVATIONS

Article 19

Formulation of reservations

A State or an international organization may, when signing, ratifying,
formally confirming, accepting, approving or acceding to a treaty,
formulate a reservation unless:

(a) the reservation is prohibited by the treaty;

(b) the treaty provides that only specified reservations, which do not
include the reservation in question, may be made; or

(c) in cases not falling under sub-paragraphs (a) and (b), the
reservation is incompatible with the object and purpose of the treaty.

Article 20

Acceptance of and objection to reservations

1. A reservation expressly authorized by a treaty does not require any
subsequent acceptance by the contracting States and contracting
organizations or, as the case may be, by the contracting organizations
unless the treaty so provides.

2. When it appears from the limited number of the negotiating States and
negotiating organizations or, as the case may be, of the negotiating
organizations and the object and purpose of a treaty that the application
of the treaty in its entirety between all the parties is an essential
condition of the consent of each one to be bound by the treaty, a
reservation requires acceptance by all the parties.

3. When a treaty is a constituent instrument of an international
organization and unless it otherwise provides, a reservation requires the
acceptance of the competent organ of that organization.

4. In cases not falling under the preceding paragraphs and unless the
treaty otherwise provides:

(a) acceptance of a reservation by a contracting State or by a
contracting organization constitutes the reserving State or international
organization a party to the treaty in relation to the accepting State or
organization if or when the treaty is in force for the reserving State or
organization and for the accepting State or organization;

(b) an objection by a contracting State or by a contracting
organization to a reservation does not preclude the entry into force of
the treaty as between the objecting State or international organization
and the reserving State or organization unless a contrary intention is
definitely expressed by the objecting State or organization;

(c) an act expressing the consent of a State or of an international
organization to be bound by the treaty and containing a reservation is
effective as soon as at least one contracting State or one contracting
organization has accepted the reservation.

5. For the purposes of paragraphs 2 and 4 and unless the treaty
otherwise provides, a reservation is considered to have been accepted by
a State or an international organization if it shall have raised no
objection to the reservation by the end of a period of twelve months
after it was notified of the reservation or by the date on which it
expressed its consent to be bound by the treaty, whichever is later.

Article 21

Legal effects of reservations and of objections to reservations

1. A reservation established with regard to another party in accordance
with articles 19, 20 and 23:

(a) modifies for the reserving State or international organization in
its relations with that other party the provisions of the treaty to which
the reservation relates to the extent of the reservation; and

(b) modifies those provisions to the same extent for that other party
in its relations with the reserving State or international organization.

2. The reservation does not modify the provisions of the treaty for the
other parties to the treaty inter se.

3. When a State or an international organization objecting to a
reservation has not opposed the entry into force of the treaty between
itself and the reserving State or organization, the provisions to which
the reservation relates do not apply as between the reserving State or
organization and the objecting State or organization to the extent of the
reservation.

Article 22

Withdrawal of reservations and of objections to reservations

1. Unless the treaty otherwise provides, a reservation may be withdrawn
at any time and the consent of a State or of an international
organization which has accepted the reservation is not required for its
withdrawal.

2. Unless the treaty otherwise provides, an objection to a reservation
may be withdrawn at any time.

3. Unless the treaty otherwise provides, or it is otherwise agreed:
(a) the withdrawal of a reservation becomes operative in relation to a
contracting State or a contracting organization only when notice of it
has been received by that State or that organization;

(b) the withdrawal of an objection to a reservation becomes operative
only when notice of it has been received by the State or international
organization which formulated the reservation.

Article 23

Procedure regarding reservations

1. A reservation, an express acceptance of a reservation and an
objection to a reservation must be formulated in writing and communicated
to the contracting States and contracting organizations and other States
and international organizations entitled to become parties to the treaty.

2. If formulated when signing the treaty subject to ratification, act of
formal confirmation, acceptance or approval, a reservation must be
formally confirmed by the reserving State or international organization
when expressing its consent to be bound by the treaty. In such a case the
reservation shall be considered as having been made on the date of its
confirmation.

3. An express acceptance of, or an objection to, a reservation made
previously to confirmation of the reservation does not itself require
confirmation.

4. The withdrawal of a reservation or of an objection to a reservation
must be formulated in writing.

Author: international