Treaties follow an unwritten template, from gerund-filled preambles to formal dates
No rule dictates what a treaty must look like, yet since the late 19th century most share a strikingly consistent shape. They open by naming the High Contracting Parties, often in one enormous sentence whose paragraphs begin with words like desiring or recognizing, and they close with a date spelled out entirely in words.
After the preamble, the phrase have agreed as follows usually marks where the real commitments begin, set out in numbered articles grouped under chapters when the text runs long. Envoys traditionally exchange documents proving their full powers to act, though a head of state, head of government or foreign minister needs no such paper. The closing section, called the eschatocol, typically starts with in witness whereof, then records the place and date. The United Nations Charter, for instance, records its San Francisco signing in 1945 with the day, month and year all written out in full words.
Signing does not always bind a country. A pre-authorised signature can commit a state at once, but more often it simply authenticates the wording, leaving consent to later ratification through legislation or executive action. Nothing obliges a signatory to ratify, and multilateral agreements often wait for a minimum number of ratifications before taking effect. Reservations let a state carve out particular obligations, but only when signing or ratifying. International law once rejected them unless every party agreed; it now tolerates them so long as they do not undermine the treaty's purpose, a shift meant to attract more members.
Words carry weight here. Calling a deal a treaty implies recognising the other side as sovereign, so governments choose labels carefully; within the United States, agreements among states are called compacts. The UN Charter, itself a treaty, requires registration before an agreement can be invoked at the UN, a rule aimed at the secret pacts that fed conflicts in the 19th and 20th centuries. Numbers can mislead as well: each bilateral treaty between Switzerland and the European Union has seventeen parties.
The Vienna Convention on the Law of Treaties, adopted on 22 May 1969, codified these practices and took effect in 1980. By May 2026 it had 119 ratifications.
Source: Treaty
