Use the Custom tab to associate the patient to items from your Custom reference list. This area is completely user-definable. Some offices use this area to list a patient's preferred pharmacy, or indicate medical study participation. You can run reports on your Custom entries using the MacPractice Drawer or the Patients marketing report.
Click the green plus above the custom table to open up the search window where you may either search for or select a custom record from the list. If the record is not present, use the plus button to create a new one (you can also create custom entries through References).