There are 2 flags that can be set.

1. First Appointment Flag - In Settings / Configuration / Advanced / Company Settings, set the “First Appointment Flag” to Yes.  The first appointment booked for a new client to the business will display “First Appt” in red on the company calendar.  If the appointment is marked as a no show or canceled, the “First Appt” notation will remain on any future bookings until a completed appointment date has been passed.
2. First Appointment Service Provider - In Settings / Service Providers / Schedules, each Service Provider can set the “First Appointment Flag” to Yes. The first appointment a client books with that Service Provider will display “First Appt SP” in red on the company calendar.  If the appointment is marked as a no show or canceled, the “First Appt SP” notation will remain on any future bookings until a completed appointment date has been passed. 
3. First Appointment Stand-Alone Resource - In Settings / Resources / Schedules, each Stand-Alone Resource can set the “First Appointment Flag” to Yes. The first appointment a client books with that Stand Alone Resource will display “First Appt SP” in red on the company calendar.  If the appointment is marked as a no show or canceled, the “First Appt SP” notation will remain on any future bookings until a completed appointment date has been passed. 

If you are moving from a paper system and have no electronic client list to import, do not set these options to “Yes” as every client will be considered First Appointment.  You can set a “First Appointment With Us” Booking Field in Settings / Booking Fields to capture those clients that are new to your business. Note, Optional or Mandatory under the Company column, must be selected in order to display the client response in the appointment details in your company calendar.