April 1993 IN VOGUE: You know you're a fashion victim when you:Flash Chanel briefs above the waistband of your trousers. Only wear a Tiffany ring on a leather thong around your neck.Want to borrow your brother's old Adidas trainers. Like platforms higher than three inches. Rip holes in a new cashmere sweater. Bare your midriff in Bond Street. Button up cardigans wrongly.