McDonald's lost yet another battle to the Irish fast food chain Supermac's, to exclusively claim the 'Mc' trademark on some of its food products within the EU. The European Union Intellectual Property Office ruled that McDonald's had not proved genuine use of the 'Mc' prefix on its trademarked products, after Supermac's second complaint and lawsuit this year. However, McDonald's has retained its right to own the trademark on chicken nuggets and some sandwich products.