order and disorder
More letters: the A of anarchy and the O of order. Proudhon, who we really should know more about and who said in 1840 that property is theft, wrote in The Confessions of a Revolutionary that 'anarchy is order without power', or often quoted as 'anarchy is the mother of order', slightly different in meaning. Proudhon and Marx correspondid and some of the basic tenets of communism, such as wealth should be transferred from capitalists to workers comes out of this relationship.
Black is the colour of anarchy, black for absence.
The A in an O was first used by the International Workers Association in Italy in 1868, but only became a commonly seen symbol in 1968, used by the Circolo Sacco e Vanzetti. Sacco and Vanzetti were anarchists in early 20th century USA, whose conviction and execution for murder in 1920 remains controversial and unresolved. Italian anarchist history is complex and long. At its most utopian, anarchy is an extreme socialism, and is against class, violence and materialism. It hoped for revolution without violence, although violence seems to have characterised most of its actions.
But it is an easy cipher to mark on walls and has come to represent a general disaffection with government structures and all their systems of order. Can there be order without power? We should all read Orwell's Animal Farm again.