The silkscreen diagram for the switch pads is also used for pots. The number 1 is a guide for using the number 1 lug of the pot to provide correct rotation.
When installing switches, the number 1 does not have any particular meaning. You can install a SPST switch into either pads.Using a SPDT switch, just install the middle lug to the middle pad. The other lugs can be installed into either remaining pads.