If a tee time is filled with members, guests or Xs (Xs=TBD), only the members in that particular tee time may alter the reservation. If the tee time is not full, other members may enter the reservation and add themselves to the tee time. Whenever there is a modification to the tee time, however, everyone in the group is notified via an automatic email confirmation of the change as well as who made the change. ForeTees always lets you know the status of your tee times.