<?xml  version="1.0"?>
<!-- syntax test for Production 63-->
<!DOCTYPE animal SYSTEM "ibm63n04.dtd"
[
<!ELEMENT animal ANY>
<!ELEMENT tiger (#PCDATA)>
<!ATTLIST animal a (tiger) #REQUIRED> 
]>
<animal a = "TIGER1">
Negative test.  Missing required field(The keyword IGNORE is missing).
</animal>