Takeovers in the UK (meaning acquisitions of public companies only) are governed by the City Code on Takeovers and Mergers, also known as the 'City Code' or 'Takeover Code'. The rules for a takeover can be found in what is primarily known as 'The Blue Book'. The Code used to be a non-statutory set of rules that was controlled by city institutions on a theoretically voluntary basis. However, as a breach of the Code brought such reputational damage and the possibility of exclusion from city services run by those institutions, it was regarded as binding. In 2006, the Code was put onto a statutory footing as part of the UK's compliance with the European Takeover Directive (2004/25/EC).