1 <?xml version="1.0"?> 2 <!DOCTYPE book [ 3 <!ELEMENT book (doc)*> 4 <!ELEMENT doc (isid)*> 5 <!ELEMENT isid EMPTY> 6 <!ATTLIST isid myid ID #IMPLIED> 7 ]> 8 <book> 9 <doc> 10 <isid myid="mine"/> 11 <isid myid="dup"/> 12 </doc> 13 <!-- including another XML document with IDs --> 14 <doc xml:base="../ents/ids.xml"> 15 <isid myid="dup"/> 16 <isid myid="foo"/> 17 <isid myid="bar"/> 18 </doc> 19 </book> 20
