Austria has banned new car number plates which have hidden codes symbolising support for neo-Nazi or other extremist causes.<br /><br /> More than 30 number and letter combinations for personalised plates are being made illegal.<br /><br /> An anti-fascist group that drafted the list, the Mauthausen Committee, says there has been a developing trend for such practice among far-right supporters.<br /><br /> But the ban only covers new registrations. People with existing plates can keep them. <br /><br /> Austria has some of the toughest laws against far-right glorification.