1 <!DOCTYPE doc

     2 [

     3 <!ELEMENT doc EMPTY>

     4 <!NOTATION a SYSTEM "a">

     5 <!--should fail at this AttlistDecl, before NOTATION decl-->

     6 <!ATTLIST doc att NOTATION (a|0b) #IMPLIED>

     7 

     8 

     9 

    10 <!NOTATION 0b SYSTEM "0b">

    11 ]>

    12 <doc/>