Chapter 3 addresses the suggestion that for a special regime to exist, there must be a mutual engagement of community members. As the chapter argues, in the context of international law, a mutual engagement among a group of international law specialists can be inferred from their participation in a distinct legal discourse, and from their further specialization and distinct way of ascribing functions to legal agents. More specifically, it can be inferred from: the publication of specialized international law journals; the way of organization of conferences and workshops; the creation of inter-governmental organization; the work of NGOs; the specialized research profile of international scholars and description of chairs; their separation of tasks and division of labour; and the function that they ascribe to the judiciary and to the international legal scholar.