In principle, refers to any formal or semi-formal process of informing a third party of a fact or event. However, it generally refers to a formal requirement that an official body be notified of certain facts or events. In particular, in competition law it refers to the formal notification of a competition authority of an agreement that may have anticompetitive effects, seeking approval or exemption of the agreement. This notification system was, until 2004, an important aspect of European Competition law. A Form A/B was normally filed on any potentially anticompetitive agreement. Notification in EU law still applies to concentrations (e.g., mergers, full function joint ventures) using a Form CO (short form or long form).