<?IS10744 arch name="express-rep"
 public-id="ISO 10303-2x//DOCUMENT XML Representation of EXPRESS-Driven Data//EN"
 dtd-system-id="p2x.dtd"
?>
<!DOCTYPE MyExpressData [
 <!ELEMENT et
   (eid,
    stuff+)
 >
 <!ATTLIST et
   express-rep
     NAME
     #FIXED "entitytype"
 >
 <!ELEMENT eid
   (#PCDATA)+
 >
 <!ATTLIST eid
   express-rep
     NAME
     #FIXED "entity_id"
 >
]>
<MyExpressData>

...
<et><eid>length_unit</eid>
...
</et>
...
</MyExpressData>