Users can use Feature Access Codes (FAC) to activate and deactivate features from their telephones. A user who knows the FAC for a feature does not need a programmed button to use the feature. For example, if the FAC for the Last Number Dialed is *33, then users can re-dial a telephone number by entering the FAC, rather than requiring a Last Number Dialed button. Many features already have factory-set feature access codes. You can use these default codes, or you can change them to codes that make more sense to you. However every FAC must conform to your dial plan and must be unique.