Rega 300 switch Question

I have a Rega 300 on a Nottingham Dais as the second arm can someone enlighten me as to what the small switch just behind the arm rest clip is for?
It has settings of 0-1-2 it is set on 1 now.
There is nothing about it in the setup paper
Thanks for any help
If it slides front to back that would be your anti-skate adjustment.
Correct--it is the antiskate, which operates magnetically.
Thanks Guys