Besides the treaty, which is the most formal international agreement, there may be various other methods of expressing the terms of international agreements. The importance of the matter contained in the various documents is not necessarily in proportion to their formality.
The terms "convention" and "treaty" are very generally used interchangeably, though strictly the scope of a convention is less broad, and usually applies to some specific subject, as to the regulation of commerce, navigation, consular service, postal service, naturalization, extradition, boundaries, etc. The terms below are often used loosely in practice.
(a) A protocol, or procès verbal, is usually in the form of official minutes, giving the conclusions of an international conference and signed at the end of each session by the negotiators. This does not require ratification by the sovereign as in the case of treaties and conventions, though it is equally binding upon the good faith of the states concerned. Ordinarily the persons signing the protocol have been duly authorized by their respective states in advance. The term "protocol" is sometimes applied to the preliminary draft of an agreement between two or more states as to the agreements entered into by negotiators in preparation of a more formal document, such as a treaty or convention.[270]
(b) Declarations are usually documents containing reciprocal agreements of states, as in granting equal privileges in matters of trade-marks, copyrights, etc., to the citizens of each state. The term is used for the documents, (1) which outline the policy or course of conduct which one or more states propose to pursue under certain circumstances, (2) which enunciate the principles adopted, or (3) which set forth the reasons justifying a given act.
(c) The terms "memoranda" and "memoires" are used to indicate the documents in which the principles entering an international discussion are set forth, together with the probable conclusions. These documents may be considered by the proper authorities, e.g. may be sent to the foreign secretaries of the states concerned, and contre-memoires may be submitted. These documents are generally unsigned.
(d) Besides the above, there may be in diplomatic negotiations letters between the agents, in which the use of the first or second person is common, and notes, which are more formal and usually in the third person. These letters, if made public, may have much force, as in the case of the collective note of the powers commonly called the "Andrassy note," by which the Powers of Europe in 1875 held that in Turkey "reform must be adopted to put a stop to a disastrous and bloody contest."
(e) When representatives of states not properly commissioned for the purpose, or exceeding the limits of their authority, enter into agreements, their acts are called treaties sub spe rati or sponsions. Such agreements require ratification by the state. This ratification may be explicit in the usual form, or tacit, when the state governs its action by the agreements.
(f) Of the nature of treaties are cartels, which are agreements made between belligerents, usually mutual, regulating intercourse during war. These may apply to exchange of prisoners, postal and telegraphic communications, customs, and similar subjects. These documents are less formal than conventions, usually negotiated by agents specially authorized, and do not require ratification, though fully obligatory upon the states parties to the agreement.[271] Here also may be named the suspension of arms, which the chief of an army or navy may enter into as an agreement for the regulation or cessation of hostilities within a limited area for a short time and for military ends. When such agreements are for the cessation of hostilities in general, or for a considerable time, they receive the name of armistices or truces. These are sometimes called conventions with the enemy. These last do not imply international negotiation.
Note. Agreements concluded between states and private individuals or corporations have not an international character, and do not come within the domain of international law. Such agreements may include:—
1. Contracts with individuals or corporations for a loan, colonization, developing a country, etc.
2. Agreements between princes in regard to succession, etc.
3. Concordats signed by the Pope as such and not as a secular prince.