[partial chunks from a schema]
Note:
* verbosity
* pure xml structure
* expanded ability to handle datatypes, regexs, (quantities?)
* use of xsd namespace

<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema">

...
<xsd:element name="comment" type="xsd:string"/>
...
<xsd:element name="quantity">
	<xsd:simpleType>
		<xsd:restriction base="xsd:positiveInteger">
	                <xsd:maxExclusive value="100"/>
	        </xsd:restriction>
	</xsd:simpleType>
...
<xsd:simpleType name="SKU">
  <xsd:restriction base="xsd:string">
     <xsd:pattern value="\d{3}-[A-Z]{2}"/>
  </xsd:restriction>
</xsd:simpleType>