- covenant: a signed written agreement between two or more parties (nations) to perform some action
- A concordat is an agreement between the Holy See of the Catholic Church and a sovereign state on religious matters. This often includes both recognition and privileges for the Catholic Church in a particular country. ...
- A type of treaty which regulates church affairs, signed between the Pope of the Roman Catholic Church and a government.
- Agreement created between two or more organisations, often to help deliver a service or set out a formal relationship, for example between the NHS and private healthcare companies, or between local and central government. ...
- A treaty between the Holy See (the Vatican) and the ruler of a sovereign nation.