XML Schema - Schema definition reuse
Direct:
<xs:include schemaLocation="character.xsd"/>
With redefinition:
<xs:redefine schemaLocation="character12.xsd">
<xs:simpleType name="nameType">
<xs:restriction base="xs:string">
<xs:maxLength value="40"/>
</xs:restriction>
</xs:simpleType>
</xs:redefine>