Suggestion for XML Schema 1.1 - Complex Type Extension

 From XML Schema Part 1: Structures, Section 2.2.13:

<Excerpt>

A complex type which extends another does so by having additional content 
model particles at the end of the other definition's content model, or by 
having additional attribute declarations, or both.
NOTE: This specification allows only appending, and not other kinds of 
extensions. This decision simplifies application processing required to 
cast instances from derived to base type. Future versions may allow more 
kinds of extension, requiring more complex transformations to effect casting.


</Excerpt>

I would like to suggest that the W3C Schema standard allow a schema author 
to specify an insertion point for each element included in the extension of 
a complexType, other than the end of the complexType.  Perhaps an attribute 
called "insert-after" could be included, with the pertinent element specified.

Kind Regards,

Joseph Chiusano