<!DOCTYPE doc
[
<!ELEMENT doc (#PCDATA|a|b|c|d)*>
<!ELEMENT a EMPTY>
<!ELEMENT b EMPTY>
<!ELEMENT c EMPTY>
<!ELEMENT d EMPTY>
<!ATTLIST a>
<!ATTLIST b >
<!ATTLIST c att CDATA #IMPLIED>
<!ATTLIST d att CDATA #IMPLIED>
<!ATTLIST
c att CDATA
 #IMPLIED
att2
 CDATA
 "second declaration is OK"
att2 CDATA
 #REQUIRED
 >
<!ATTLIST d>
]>
<doc><c/><c att2="test"/></doc>