If you've found that your patient names are suddenly missing from the Appointment Book, or have been replaced by their SMS Replies, you may have accidentally turned on Toggle SMS Replies. To correct this, simply head to Appts > Toggle SMS Replies. Your patient names should then appear in the Appointment Book again.
If the patient names have been replaced by Notes, you may have selected the Toggle between Names and Notes display option 
, which can be found in your Icons Table (below). To bring your patient names back, simply select this icon again.