What I like about the external file is that in the context of my example 
(code lists), and in particular in the context of ACORD XML reinsurance 
specification, code lists can be exchanged in the form of an XML 
document similar to the one you described. Assuming this document is 
persisted as a file, allowing the XML Schema to refer to this file could 
be useful.

That said, what I don't like with the assert co-constraint approach, is 
that I don't see how an XML editor would leverage it for code assist. 
Perhaps you could expand on how you see the assert approach with 
external XML file as you described could work for code assist.

My idea was something like:

<xs:complexType name="GenericStatus_Type">
   <xs:sequence>
      <xs:element name="StatusCode" type="xs:string"/>
      <xs:element name="Severity" type="xs:string" minOccurs="0"/>
      <xs:element name="Desc" type="xs:string" minOccurs="0"/>
   </xs:sequence>
</xs:complexType>

<xs:complexType name="Status_Type">
    <xs:restriction base="GenericStatus_Type">
       <xs:enumeration>
          <ifx:StatusCode>100</ifx:StatusCode>
          <ifx:Status>Error</ifx:Status>
          <ifx:Desc>General Error</ifx:Desc>
       </xs:enumeration>
    </xs:restriction>
</xs:complexType>

The Status_Type could be also part of a separate xs:include xsd file 
that can be easily updated dynamically given an XML document containing 
the code list. Code assist would be quite easy too.

Guillaume

From ekimber@r... Thu Dec 20 03:40:00 2007
Received: from wiggum.w