The property Available only if controls whether elements are displayed or not depending on the current state or user.

When only one state or a user group is selected, the form element is displayed only when the form is in the selected state or viewed by a user of the selected user group. For each state and user group there is also the opposite option to display a form element only when it is not in the selected state or not viewed by the selected user group. For example, when you want display a form element only when a user fills out the form for the first time, you can select the option no state.

If both a state and a user group are selected, the form element is displayed only when the form is both in the selected state as well as opened by a user belonging to one of the selected user groups.