SB Anchor create a Joint between Rigid Bodies and Softbody vertex. Vertex selection can use edit/editable modifier or vertex selection set.

Icon Size:
Defines size of the icon in the viewport.

Anchor Object:
Anchor object is base object of anchor. You can pick dynamic / static / kinetic object for this. If you don’t use this option, object constraint to this icon position.

Disable Collision:
When checked, disable collision between Anchor object and softbody object.

Softbody Object:
Softbody object is anchored object. You have to pick softbody object for this.

Vertex Set:
Defines which vertex selection set use for. -1 means latest modifier vertex selection. And 0 and later means vertex selection set.

Influence:
Defines influence of anchor.