Attributes for the <componentRefList> Element

The <componentRefList> element has one optional attribute, modifier, which specifies the override requirements of the resource. If this attribute is specified, the value must be FINAL, which means that derived components cannot declare new <componentRef> elements.

If this attribute is omitted, derived components can add new <componentRef> elements. In either case, derived components can override the <type> element and nonfinal inherited <componentRef> elements. If the base component's <componentRefList> modifier attribute is FINAL, the modifier attribute of the derived component must also be FINAL.

When modifier is FINAL for the <componentRefList> element, the modifier attribute of each contained <componentRef> is not necessarily FINAL.