Example: Student's Workplan

  <workplan xlink:title="Nevada Barr's workplan" xlink:type="extended">
    <relation xlink:type="arc" xlink:from="student" xlink:to="course"/>
    <relation xlink:type="arc" xlink:from="student" xlink:to="advisor"/>
    <relation xlink:type="arc" xlink:from="marks"   xlink:to="student"/>
    <data xlink:type="locator"  xlink:role="student" 
      xlink:href="http://brunel.ac.uk/sr1003.xml"/>
    <data xlink:type="locator"  xlink:role="course"
      xlink:href="http://brunel.ac.uk/cs5011A.xml"/>
    <data xlink:type="locator"  xlink:role="course"
      xlink:href="http://brunel.ac.uk/cs5012A.xml"/>
    <data xlink:type="locator"  xlink:role="advisor"
      xlink:href="http://brunel.ac.uk/advisor/smith.xml"/>
    <marks xlink:type="resource" xlink:role="marks"
      xlink:label="marks.html">7.8</marks>
  </workplan>

Note that identifaction is made based on role; an arc can be a shorthand for several links!