<element name="example" xmlns="http://relaxng.org/ns/structure/1.0">
<zeroOrMore>
<attribute>
<anyName>
<except>
<name>xml:space</name>
</except>
</anyName>
</attribute>
</zeroOrMore>
<optional>
<attribute name="xml:space">
<choice>
<value>default</value>
<value>preserve</value>
</choice>
</attribute>
</optional>
</element>