Re: [xml-dev] Re: Designing Schemas for Backward and Forward Compatibility - XML Schema, Relax NG, Schematron

Let me try to rephrase the question. In the beginning, when the version 
1 schema is like the following:

<element name="Book">
   <complexType>
       <sequence>
           <element name="Title" type="string"/>
           <element name="Author" type="string"/>
           <element name="Date" type="date"/>
           <element name="ISBN" type="string"/>
           <element name="Publisher" type="string"/>
           <element name="Other" minOccurs="0">
               <complexType>
                   <sequence>
                       <any minOccurs="0" maxOccurs="unbounded" 
processContents="lax"/>
                   </sequence>
               </complexType>
           </element>
       </sequence>
   </complexType>
</element>

people already want to take advantage of the <other> element and put 
various things in it. So one person would have:

<Book>
   <Title>My Life and Times</Title>
   <Author>Paul McCartney</Author>
   <Date>1998</Date>
   <ISBN>1-56592-235-2</ISBN>
   <Publisher>McMillan Publishing</Publisher>
   <Other>
       <namespace2:tag2>blah blah</namespace2:tag2>
   </Other>
</Book>

and another person would have:

<Book>
   <Title>My Life and Times</Title>
   <Author>Paul McCartney</Author>
   <Date>1998</Date>
   <ISBN>1-56592-235-2</ISBN>
   <Publisher>McMillan Publishing</Publisher>
   <Other>
       <namespace1:tag1>blah</namespace1:tag1>
   </Other>
</Book>

Now we want to add a <NumPages> in the new version of the schema, but 
the "blah blah" thing in the old XML files prevent them to be validate 
in the new version of schema.

Any solution to this?

Zhiwu