Hello Vougue Couture,

Thanks for reaching out to us. When this option is enabled, all customers who had appointments in the past marked as “No Show”, will have a Tag (different color across their names) in the Customer’s profile and in the Appointments section. A gray tag indicates the customer who failed to show up once; a yellow tag indicates the customer who failed to show up twice; and the red tag indicates the customer who failed to show up 3 or more times. You can find more information on this link