<!DOCTYPE doc [ <!ELEMENT doc (#PCDATA | ns:a | ns:b)*> <!ATTLIST doc
attr CDATA #REQUIRED xmlns:ns CDATA #IMPLIED>
<!ELEMENT a EMPTY> <!ELEMENT b (#PCDATA)> ]> <ns:doc ns:attr=βvalβ xmlns:ns=βwww.example.org/test/β>
<ns:a/> <ns:b>first line</ns:b> <ns:b>second line</ns:b>
</ns:doc>