The XML schema editor has a built-in mechanism to handle referential integrity issues. When you delete certain nodes, clean up for any nodes affected will automatically occur.
<schema> <element name="comment" type="string"> <complexType name="Items"> <sequence> <element ref="comment"> </sequence> </complexType> </schema>
If the global element (comment) was deleted, all references to it would be in error. However, when you delete the global element, the XML schema editor will clean up using the following algorithm: