Straight edge (sometimes abbreviated sXe or signified with XXX or X) is a subculture of hardcore punk whose adherents refrain from using alcohol, tobacco and other recreational drugs, in a reaction to the excesses of punk subculture. For some, this extends to refraining from engaging in promiscuous sex, following a vegetarian or vegan diet, and/or not using caffeine or prescription drugs. The term was adopted from the 1981 song "Straight Edge" by the hardcore punk band Minor Threat.