XSD: Allow elements from different namespace anywhere in a sequence

Question

I\'ve been trying out the following. I want to create an XSD for an XML where certain elements are allowed to appear only once and need to be valid, and elements from other

Answer 1

In XSD 1.1 you can do this very easily by defining an open content model:

<xs:complexType ...>
  <xs:openContent mode="interleave">
    <xs:any namespace=.../>
  </xs:openContent>
  ... regular content model ...
</xs:complexType>

There's no easy way to do it in 1.0; you just have to put an optional wildcard in every possible position.