What can be done to make an ethics code work? It is an important question, given that this once voluntary tool is now a virtual obligation, especially for multinationals...New York Stock Exchange listing rules require companies to have a publicly displayed code of business conduct and ethics...In the UK, it has been best practice since the 1992 Cadbury report on corporate governance for boards to draw up and publicise a code of ethics or statement of business principles...But the mere existence of a code is not enough. [refers to Citigroup, Ogilvy & Mather (part of WPP)]