An acronym for "Yours in the struggle". Used as a sign off or signifier. Popular among national liberation, nationalist or revolutionary movements. Implies a shared purpose and cause of intense or revolutionary commitment. Like "-power", it expanded from an indigenous or Third World, minority political movement phrase to being popular among nationalists, revolutionaries and psuedo revolutionaries of a wide variety of groups.
Black Panther rep: I can't believe that the Afrikaners use Y.I.T.S. as a sign off now!
American Indian Movement rep: Better them than a Berkeley student protesting the cafeteria serving meat. God I hate these people.
...If the man tries to hold you down, put a slug in the left side of his head, put his mind right, ya dig? Y.I.T.S., Mumia
...You probably don't want to spit at the congressman even if he deserved it. This is a long term movement and we need leaders in the Tea Party who are committed to changing this government by whatever means necessary. See you when you get out. Y.I.T.S., Herman Goering