<!DOCTYPE root [

 <!NOTATION default_notation SYSTEM "perl.exe">

 <!ENTITY ent "gen_ent">
 <!ENTITY dq '"'>
 <!ENTITY sq "'">
 <!ENTITY bothq "&quote;'">
 <!ENTITY ent "second_def">
 <!ENTITY % pent "param_ent">
 <!ENTITY % pent "second_def">

 <!ENTITY % any "ANY">

 <!ELEMENT root ANY>
 <!ELEMENT a ANY>
 <!ATTLIST a
	attr CDATA "&ent;">
]>

<root>
 <a attr="uses &ent;">Entity ref &ent; in text</a>
</root>