This chapter addresses the suggestion that for a special regime to exist, community members must have a shared repertoire. In the context of international law, to claim that a group of international law specialists have a shared repertoire is to assert that they consider the use of certain rhetorical tools appropriate. As Chapter 5 argues, the existence of such a presupposition can be inferred from, amongst others, the use by specialists of distinct concepts, a distinct terminology, a distinct method, and distinct theories.

When a new state comes into being, it is important to know which treaties, bilateral or multilateral, applied to it when it was part of another state, and which still apply to it. The Vienna Convention on Succession of States in Respect of Treaties 1978 seeks to regulate the issue, but only twenty-three states were parties by July 2022. Certain customary law principles, which the chapter outlines, can, however, be stated with reasonable confidence. The chapter also examines the case of former colonies and other overseas territories, and the approaches known as universal succession and the clean slate doctrine. It takes a detailed look at the two German states, the former Soviet Union, the former Yugoslav Republics, the former Czechoslovakia, and Hong Kong and Macau. It also discusses the role of the depositary in cases of treaty succession.