‘Private ordering’ is a term that is often mentioned, but used inconsistently. In the age of platformised communication, it has become an essential concept for understanding the dynamics of rule-setting and rule-implementation on platforms. Private ordering in the narrower sense refers to the development of rules by one or more private actors, usually businesses, in relation to the (digital) services they offer and the conditions under which they offer them. In the case of private ordering in the media sector, the behaviour being regulated is communication. This article describes its genesis, challenges and future in the light of a growing demand for the inclusion of public values in self-given orders, and analyses its role in different media sectors, in public relations work by governments and on online platforms. It focuses on private ordering by individual companies and organisations and thus excludes sector-wide standards and other cases of (regulated) self-regulation.