The New button will append a new rule, if you want to insert a rule, you may right-click on list and select Insert-to-before or Insert-to-following. Insert-to-before will insert a new rule to the before of you selected item. Insert-to-following will insert a new rule to the following of you selected item.

Edit a rule

Double-click the rule you want to edit, or click Edit button after the rule selected. Changes the rule in popup dialog box and click OK, and lastly click Apply button to apply the changes. About how to set the rule please click one you want to view:

Delete a rule or multi-rules

Select a rule or a group of rules and click Delete button to delete it. Presses Ctrl button and click the rule, you may select more noncontiguous rules. lastly, you need to click the Apply button to apply the changes.