This dialog allows you to define any number of filter rules available to Mahogany. In a seaparate dialog (2.2.2) you can then pick any rule from the list and assign it to a folder. As you can have different sets of rules for each folder and might want to share rules for some folders, this dialog simply sets up rules and you can later specify for which folders to use them. When editing or adding a new filter rule, you will get to the following dialog: