According to the European Court of Justice a trade mark must unequivocally point to the goods of one undertaking without any possibility of confusion, in order to fulfill its essential function. However, as this book demonstrates, there are a number of points throughout the trade mark system where multiple undertakings share the same name, either unwillingly, or by consent of the parties involved. The book attempts to identify the points at which names are shared, to examine the practical and theoretical implications of this sharing for the parties involved and to analyse what we can learn from the sharing process about the nature of, and interests protected by, the trade mark system.