throw signs
v. phr.— «They “throw signs”-bending fingers to form “C,” for Crip, or “CK,” for Crip Killer, “B” for Blood, or “BK” for Blood Killer.» —“Gang Tension At School, Survival Comes First” by Judy Pasternak Los Angeles Times Feb. 5, 1989. (source: Double-Tongued Dictionary)