Heya, JSF 1.2 XSD does contains the uniqueness constraint (MyFaces' XSD): <xsd:element name="faces-config" type="javaee:faces-configType"> <xsd:unique name="faces-config-converter-ID-uniqueness"> <xsd:selector xpath="javaee:converter"/> <xsd:field xpath="javaee:converter-id"/> </xsd:unique> <xsd:unique name="faces-config-converter-for-class-uniqueness"> <xsd:selector xpath="javaee:converter"/> <xsd:field xpath="javaee:converter-for-class"/> </xsd:unique> <xsd:unique name="faces-config-validator-ID-uniqueness"> <xsd:selector xpath="javaee:validator"/> <xsd:field xpath="javaee:validator-id"/> </xsd:unique> <xsd:unique name="faces-config-managed-bean-name-uniqueness"> <xsd:selector xpath="javaee:managed-bean"/> <xsd:field xpath="javaee:managed-bean-name"/> </xsd:unique> </xsd:element> Anyway, that won't protect anyone from using the same name in different config files though. <dennisbyrne(a)apache.org&gt;