Section 235 of the Constitution of South Africa contains a promise of potential self-determination of language and cultural communities. An essential question arising from this promise is how an individual’s freedom of association interacts with the ability of a community to determine its membership. This article reflects on this question with reference to standards developed in international law and practices in the constitutional law of selected case studies. Whereas international law sets a universal standard of free association, states have developed practices whereby the individual’s right to free association is recognised, but where there are also some measures allowed to ensure that an individual is indeed accepted by and part of the community. Any conflicts that arise are, generally speaking, subject to a form of judicial review.