The objective in customary law is to find evidence of state practice by using sources such as:
- records of a state's foreign relations and diplomatic practices, as set forth in official statements, diplomatic exchanges;
- a state's domestic court decisions;
- a state's internal legislation concerning its international obligations;
- newspaper reports of actions taken by states, statements made by government spokesmen to Parliament, to the press, at international conferences; and
- in resolutions, declarations & legislative acts of intergovernmental organizations.