Index DTD
<!ELEMENT index (file | dir)* >
<!ATTLIST index id CDATA #IMPLIED >
<!ATTLIST index base CDATA #IMPLIED >
<!ATTLIST file path CDATA #REQUIRED >
<!ATTLIST file id CDATA #IMPLIED >
<!ATTLIST file size CDATA #IMPLIED >
<!ATTLIST file mime CDATA #IMPLIED >
<!ATTLIST file info CDATA #IMPLIED >
<!ELEMENT dir (file | dir)* >
<!ATTLIST dir path CDATA #REQUIRED >