How the Tag feature works in the Address Book?

The “Tag” feature in the Address Book enables you to add a “tag” to address book entries, then “Filter by Tag” to choose from a smaller list. For example, if you have may different IRS and state tax offices in your address book, you can add tags such as “IRS, Ogden”, “IRS, Cincinnati”, “IRS, Louisville”, and so on. Then use the Filter by Tag option to narrow the list to just IRS offices, or to a specific IRS office.