1<?xml version="1.0"?>
2<element xmlns="http://relaxng.org/ns/structure/1.0" name="device">
3    <choice>
4      <group>
5	<attribute name="link">
6	  <value>ethernet</value>
7	</attribute>
8	<optional>
9	  <element name="ethernet-element">
10	    <text/>
11	  </element>
12	</optional>
13      </group>
14      <group>
15	<attribute name="link">
16	  <value>serial</value>
17	</attribute>
18	<optional>
19	  <element name="serial-element">
20	    <text/>
21	  </element>
22	</optional>
23      </group>
24    </choice>
25</element>
26