Form index returns the z-index of the form element. If two elements overlap,
then the element with higher Z index is displayed above the form element with lower Z index.
In case of form inheritance, form index is evaluated in the context (form) where property is defined.
Elements which have child form as context will always be on top of elements which have parent form.
If element is overridden in child form but form index property is still inherited its context is still parent form. |