<!ELEMENT database    (themes?, persons?, issues?, articles?)>
  <!ELEMENT themes      (theme+)>
    <!ELEMENT theme       (title*)>
      <!ELEMENT title       (PCDATA)>
  <!ELEMENT persons     (person+)>
    <!ELEMENT person      ((email, name, homepage?, nickname?, desc*, team*)|EMPTY)>
      <!ELEMENT email       (PCDATA)>
      <!ELEMENT name        (PCDATA)>
      <!ELEMENT homepage    (PCDATA)>
      <!ELEMENT nickname    (PCDATA)>
      <!ELEMENT desc        (ANY)>
      <!ELEMENT team        (EMPTY)>
  <!ELEMENT issues      (issue+)>
    <!ELEMENT issue       (title*, published?, file*)>
      <!ELEMENT published   (EMPTY)>
      <!ELEMENT file        (PCDATA)>
  <!ELEMENT articles    (article+)>
    <!ELEMENT article     (title+, file?, person*, abstract, 
                           issue?, theme, translation+, proofread?)>
      <!ELEMENT abstract    (PCDATA)>
      <!ELEMENT translation (person, reserved, finished?, proofread?)>
        <!ELEMENT reserved    (PCDATA)>
        <!ELEMENT finished    (PCDATA)>
        <!ELEMENT proofread   (person, finished)>

<!ATTLIST theme       id            CDATA         #IMPLIED
                      href          CDATA         #IMPLIED>
<!ATTLIST title       xml:lang      CDATA         #REQUIRED>
<!ATTLIST person      id            CDATA         #IMPLIED
                      href          CDATA         #IMPLIED
                      status        (non-active|active|idle)   
                                                  "non-active">
<!ATTLIST desc        xml:lang      CDATA         #REQUIRED>
<!ATTLIST team        xml:lang      CDATA         #REQUIRED>
<!ATTLIST issue       id            CDATA         #IMPLIED
                      href          CDATA         #IMPLIED>
<!ATTLIST article     id            CDATA         #REQUIRED
	              xml:lang      CDATA         #REQUIRED
                      type          (article|coverpage)
                                                  "article">
<!ATTLIST file        xml:lang      CDATA         #REQUIRED
                      type          (target|meta) "target">
<!ATTLIST translation from          CDATA         #REQUIRED
                      to            CDATA         #REQUIRED>