List of xs:ID - what am I missing

[chris]

For reasons I rather not go into, I'm looking to generate a type of "list of xs:ID" think of of them as aliases

with XSV I can get round to acually entering a list but they are not recognised as ID just NMTOKENS and when I use them I get ID not declared

What am I missing?

I generated a little example using inline schemas, to show the issue. Don't even try to use XMLSpy
1) No inline support
2) will not cope with

<xs:simpleType>
    <xs:list itemType="xs:ID"/>
</xs:simpleType>

Any Ideas
Chris

<?xml version="1.0" encoding="UTF-8"?>
<arbitrarytag xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:noNamespaceSchemaLocation="#local">
<xs:schema id="local">
<xs:element name="root" >
        <xs:complexType>
            <xs:choice>
                    <xs:element name="Node" >
                        <xs:complexType>
                            <xs:attribute name="In" type="xs:IDREFS" />
                        </xs:complexType>
                    </xs:element>
            </xs:choice>
            <xs:attribute name="In">
                        <xs:simpleType>
                <xs:list itemType="xs:ID"/>
            </xs:simpleType>
</xs:attribute>
        </xs:complexType>
</xs:element>
</xs:schema>
<root In="CCG FRED">
    <Node In="CCG FRED" />
</root>
</arbitrarytag>