Each point, edge, polygon and curve menu has a Do Nothing Action. This Action prevents use of its associated element when hovering over the mesh. This is helpful if you want to only preform certain Actions by blocking mis-clicks.
For example, if you enable the Do Nothing action for points then clicking on a point will result in the Action being applied to the associated edges instead. If you also enable Do Nothing for edges then you will only be able to affect polygons even if you click on a point or edge by mistake.