xmlschema-core/src/test/resources/attributref.xsd

<xs:schema elementFormDefault="qualified"
           xmlns:xs="http://www.w3.org/2001/XMLSchema"
           xmlns:tns="http://tempuri.org/attribute"
           targetNamespace="http://tempuri.org/attribute">

    <xs:element name="TestAttributeReferenceElement" type="tns:TestAttributeReferenceType"/>
    <xs:attribute name="TestAttribute1" type="xs:string"/>
    <xs:complexType name="TestAttributeReferenceType">
        <xs:sequence>
            <xs:element name="param1" type="xs:string"/>
            <xs:element name="param2" type="xs:string"/>
        </xs:sequence>
        <xs:attribute ref="tns:TestAttribute1"/>
    </xs:complexType>

</xs:schema>