1 <!DOCTYPE doc [ 2 <!ELEMENT doc (a , b* , c+)> 3 <!ELEMENT a EMPTY> 4 <!ELEMENT b (#PCDATA)> 5 <!ELEMENT c (#PCDATA)> 6 ]> 7 <doc><a/><b> but this</b><c>was not declared</c><b>seems</b></doc> 8
