Here is a short guide to help you understand the meaning of the icons displayed in appointments:
Means it’s a new customer OR that it is marked by staff (appointments can be manually marked in the 'Calendar' tab)
Means the client has arrived
Means an instant message was sent to the client
Means that a work order has been created in Lightspeed
Means a request from the client was added to this appointment or that a note was added to the appointment
Means a sale was created in Lightspeed
Mean a payment with Stripe has been made, OR a payment with Square has been made, OR an invoice was created