Can mandatory definitions be inherited?

If the association is inherited and you have not selected the All Values Required check box, then inherited-required attributes from parent will be displayed in a read-only format in the selected list and you can move additional required attributes from available list to selected list.

If the association is inherited and you have selected the All Values Required check box, then All Values Required is read-only and inherited attributes are placed in the selected list, also in a read-only format.