Booking forms can either be sent to parental or student user accounts. When setting up your club you will be asked if you would like booking forms to go to either parents or students, this is just for setting purposes and will determine who booking forms go to when you come to send them.
Club booking forms will only go to users who have a Squad in Touch account. If a parent / student sets up an account after you have sent the booking form, you will need to send them a booking form again to ensure they are able to book onto your activity.