A Class Merc - A Class Merc - Auto Gears - lk82

I have a A Class merc 1.4 auto. Im just wonder what the W/S switch is for and what i should use. The manual has something else in it. Any advice much appreciated.

A Class Merc - A Class Merc - Auto Gears - madf

Winter/Summer.

Start in higher gear in Winter to prevent wheelspin.