California M13 or S13 (South-side) gang member standing in front of painted canvas of Mexican Flag Eagle. He is wearing blue bandana mask and showing his gang sign at the Mexican Day Parade in New York City.
South-side colors are blue. Thirteen stands for M, the thirteenth letter of the alphabet. M is for Mexican Mafia.
MS13, S13, M13, are commonly worn on gang clothing or jerseys, written Old English style. The gang territory in California extends from North of Monterey to the Mexico border.