Like the include mechanism, redefine requires the external components to be in the same target namespace as the redefining schema, although external components from schemas that have no namespace can also be redefined.
The following instructions were written for the Resource perspective, but they will also work in many other perspectives.
To add a redefine element, follow these steps:
Once you have added the redefine element to your XML schema, you can redefine any of the simple and complex types, groups, and attribute groups in the XML schema you selected in the redefine element.
Related tasks
Adding an import element
Adding an include element
Related reference
XML namespaces