SixdoubleO refers to '6-00'. 600 is a set of the Black Disciples gang located in Chicago. SixdoubleO became popular after Edai, a 600 gang member, released a song titled 'SixdoubleO' which featured numerous rappers from the 600 set including RondoNumbaNine, S. Dot, and L'A Capone. The 600 set consists of rappers such as Edai, S.dot, RondoNumbaNine, Tay600, Booka, Qwap600, Huncho Hoodo,600Breezy, TheFamousSeven, Cdai, and D.Rose.