diff --git a/core/org.eclipse.cdt.core/schema/CProject.exsd b/core/org.eclipse.cdt.core/schema/CProject.exsd
index 0b981ea3c71..7de57c08957 100644
--- a/core/org.eclipse.cdt.core/schema/CProject.exsd
+++ b/core/org.eclipse.cdt.core/schema/CProject.exsd
@@ -44,13 +44,20 @@
          <attribute name="class" type="string" use="required">
             <annotation>
                <documentation>
-                  
+                  Class which implements org.eclipse.cdt.core.ICOwner
                </documentation>
                <appInfo>
                   <meta.attribute kind="java"/>
                </appInfo>
             </annotation>
          </attribute>
+         <attribute name="natureID" type="string">
+            <annotation>
+               <documentation>
+                  This is a nature ID which the owner has. This is used to restore a ICDescriptor which has been deleted.  If this is not provided the descriptor will be restore with no owner. A project with multiple natures will use the first matching nature searched in the reverse order in the Project Description.
+               </documentation>
+            </annotation>
+         </attribute>
       </complexType>
    </element>