Addresses can be assigned to one or more categories. You may create any number of categories to help organize your addresses. You can use category filtering to only show addresses belonging (or not belonging) to specified categories.
There are 2 ways to assign an address to a category. You can use the address editor to enter categories for a single address. Alternatively, you can select one or more addresses from the Address List, and then choose the Edit/Categories... menu command. (You could also right mouse click on any selected address, and choose Categories... from the popup menu.) This will bring up a dialog where you can specify the categories for all selected addresses.
Handy Address Book comes with some default categories, but you can add, edit, or delete categories from the category list. There is no limit to the number of categories you can create. To modify the list of available categories, choose the Edit Category List... button from within the category filter dialog or the category selection dialog.
To apply category filtering select the View/Categories... menu command, or press the Categories button on the toolbar. The current status of category filtering will be shown in the status bar.