Reserve currency economy, the German Deutsche Mark gained the status of the second most important reserve currency after the US dollar. When the euro was introduced on 1 January 1999, replacing the Mark, French franc and ten other European currencies, it inherited the status of a major reserve currency from the Mark. Since then, its contribution to official reserves has risen continually as banks seek to diversify their reserves, and trade in the eurozone continues to expand. Former U.S. Federal Reserve Chairman Alan Greenspan said in September 2007 that the euro could replace the U.S. dollar as the world's primary reserve currency.
European Currency Unit (U+20A0), comprises an interlaced C and E, which are the initial letters of the phrase 'European Community' in many European languages. However, this symbol was not widely used: few systems at the time could render it and in any case banks preferred (as with all currencies) to use the ISO code XEU. As the ECU was only an electronic unit of account and not a full currency, it did not have any official coins or notes that could be used for everyday transactions. However, various European countries and organisations like the European Parliament made commemorative and mock-up coins and notes.