<?xml version=“1.0”?> <element xmlns=“relaxng.org/ns/structure/1.0” name=“device”>
<choice> <group> <attribute name="link"> <value>ethernet</value> </attribute> <optional> <element name="ethernet-element"> <text/> </element> </optional> </group> <group> <attribute name="link"> <value>serial</value> </attribute> <optional> <element name="serial-element"> <text/> </element> </optional> </group> </choice>
</element>