sXe is an offshoot of
punk culture that focusses on control. Straight-edge is about controlling your life. This means no
alcohol,
narcotics,
smoking, or
promiscuous sex. Many straight-edgers also become
vegetarians or
vegans but that's not a requirement for being straight-edge. Additionally, many straight-edgers don't use
caffeine. Poison-free.
Straight-edge originated with the Minor Threat song Straight Edge. The X's come from "all-ages" punk shows where minors had X's put on their hands to show they couldn't buy alcohol. Straight-edgers started putting X's on their hands as a show of solidarity.
It seems I'm a straight-edge, though I'd never heard of it before yesterday.