If your clients reply with C then the appointment will be confirmed and if they reply with R then an appointment reschedule request will be logged. If your clients reply with X, the appointment will be canceled.

You can toggle automatic inclusion of these instructions in your reminders by checking the boxes for "Add confirm instructions to reminders", "Add reschedule instructions to reminders", and/or "Add cancel instructions to reminders" on the Reminders settings page.

If you'd like to include your own custom instructions then you can disable that setting and put your own instructions in your Reminder Template(s). For example if our Confirm and Reschedule instructions don't work for you, then you could include your own custom instructions like:

"Please reply C to confirm your appointment or X to cancel. Call us at {PhoneNumber} if you need to reschedule."

Replying C will always confirm, replying R will always reschedule, and replying with X will always cancel an appointment, regardless of whether or not these instructions are included in your message.