<optional><element name="arch"><text/></element></optional>
<optional><element name="distro"><text/></element></optional>
<optional><element name="product_name"><text/></element></optional>
+ <optional><element name="product_variant"><text/></element></optional>
<element name="major_version"><text/></element>
<element name="minor_version"><text/></element>
<optional><element name="windows_systemroot"><text/></element></optional>