The colors black and red have been used by anarchists since at least the late 1800s, though generally used by anarcho-communists. The flag was used as the symbol of the anarcho-syndicalists by the CNT during the Spanish Civil War. The black represents anarchism and the red represents leftist and socialist ideals. George Woodcock writes that the bisected black-and-red flag symbolized a uniting of "the spirit of later anarchism with the mass appeal of the First International"

Anarcho-syndicalism is a political philosophy and anarchist school of thought that views revolutionary industrial unionism or syndicalism as a method for workers in capitalist society to gain control of an economy and thus control influence in broader society. The end goal of syndicalism is to abolish the wage system, regarding it as wage slavery. The anarcho-syndicalist theory therefore generally focuses on the labor movement. The basic principles of anarcho-syndicalism are solidarity, direct action, direct democracy, and workers' self-management. Anarcho-syndicalists believe their economic theories constitute a strategy for facilitating proletarian self-activity and creating an alternative…   Read more