An item's visibility within a layout is specified by the Visibility property.
Invisible items are those that have the Visibility property set to Hidden or Collapsed. By default, when the ShowInvisibleItems property is set to null, invisible items are not displayed when layout customization is not active, and they become visible when layout customization starts. Set the ShowInvisibleItems property to true to always display invisible items. Set this property to false to hide invisible items, even in customization mode.