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<!ELEMENT package (name, date, maintainer, imports)>
<!ATTLIST package
    needs-compilation (yes|no) #REQUIRED>
<!ELEMENT maintainer (name, email)>
<!ELEMENT name (#PCDATA)>
<!ELEMENT date (#PCDATA)>
<!ELEMENT email (#PCDATA)>
<!ELEMENT imports (import*)>
<!ELEMENT import (#PCDATA)>