The term “treaty” can be used as a common generic term or as a particular term which indicates an instrument with certain characteristics.
(a) Treaty as a generic term: The term “treaty” has regularly been used as a generic term embracing all instruments binding at international law concluded between international entities, regardless of their formal designation. Both the 1969 Vienna Convention and the 1986 Vienna Convention confirm this generic use of the term “treaty”.
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 (even before the 1969 Vienna Convention on the Law of Treaties, the word “treaty” in its generic sense had been generally reserved for engagements concluded in written form).
Question to ask to know if a document is a treaty…
Is it a written document?
Is it between States?
Do the words used in the document indicate an intention to create rights and obligations under international law?
Who are the people who signed on behalf of the States and are they authorized?
What is a not important in determining treaty status…
If the text is published in the United Nations Treaty Series
The name of the document, although one may be pretty sure that a document called “Treaty on so and so” must be a treaty!
The length of the document.
Some treaties have been signed by many nations but have not yet entered into force. This is the case of instance of the Vienna Convention of 1986.