If you keep the cursor on the active checkbox in front of the course, the following message is displayed: You cannot register for the course at the moment, as the maximum number of participants has been reached. Before the beginning of studies or during the first weeks, some places may become vacant; therefore, we advise you to register on the waiting list. When a vacancy appears, you will receive a message on all your e-mail addresses entered into SIS, and the SIS Notifications. After that, you have three days (including the day when the message was sent) to register for the course or to give up the place offered. Since the time for responding is very limited, make sure to check your e-mail box regularly. (see Figure).