Hi LarryTake a look at the "IncludeInFormUndoType" property on the form. This can be combined with a counterpart property on the BO called "IncludeInFormUndo". Basically, you can have the "Undo" action applied to the PrimaryBO, AllBOs or determined by BOs that have their IncludeInFormUndo property set true.
This logic can be applied to all other "actions" like Save, Edit, Delete, New, Navigate etc.,
HTH
-=Gary