The Confederate battle flag, called the 'Southern Cross' or the cross of St Andrew, has been described variously as a proud emblem of Southern heritage and as a shameful reminder of slavery and segregation. In the past, several Southern states flew the Confederate battle flag along with the US and state flags over their statehouses. Others incorporated the controversial symbol into the design of their state flags. The Confederate battle flag has also been appropriated by the Ku Klux Klan and other racist hate groups. According to the Southern Poverty Law Centre, more than 500 extremist groups use the South Cross as one of their symbols.