<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE Sample
  [
    <!ELEMENT Sample (DataItem) >
    <!ELEMENT DataItem (#PCDATA) >
    <!ATTLIST DataItem Id ID #IMPLIED>
  ]
>

<Sample xmlns="http://iaik.at#Sample">
  <DataItem Id="DataItem">
    Some Data from IAIK
  </DataItem>
</Sample>