What we learned from the official Mercedes Benz Fashion Week Calendar, released yesterday: 1. Charlotte Ronson's finally showing in the big tent. No more sitting on laps in rows one through three. 2. Prabal Gurung's staging a proper runway show. It's scheduled for Saturday, February 13th at 4pm in the Salon. 3. Vera Wang's returning to Bryant Park after showing in her downtown store for two seasons. 4. Richard Chai's back uptown, too. 5. Ralph Lauren's on the official schedule, but he'll stage his three shows on the morning of the 18th downtown at 275 Hudson Street.