This is a standard complex control on an optional field, with form.maybenull=false and ctrl.emptyisnull=true. Since emptyisnull=true the control collapses after validation if there are no values, while the expandible control does not also if ctrl.emptisnull=true since it keeps the expanded/collapsed state in the form session.

This is a standard complex control on an optional field, with form.maybenull=false and ctrl.emptyisnull=true. Since emptyisnull=false the control does not collapses after validation if there are no values, for the same reason the output instance contains a complex value for this field also if all its sub fields are empty.

This is an expandible control that has a button that disappears after is clicked for the first time.

This is an expandible control that has a button that collapse when is clicked but only if there is no data in the sub form.

This is an expandible control that has a button that collapse without clearing state when is clicked.

This is an expandible control that has a button that collapse clearing state when is clicked. Like the first standard control has ctrl.emptyisnull=true but this one, also if has no data does not collapse after a validating submit.