Metacat

<!ELEMENT Product (Name, Developer?, Summary?, Description?)>

<!ELEMENT Developer (#PCDATA)>

<!ELEMENT Name (#PCDATA)>

<!ELEMENT Summary (#PCDATA)>

<!ELEMENT Description (Para | List)+>

<!ELEMENT Para (#PCDATA | Link)*>

<!ELEMENT List (Item+)>

<!ELEMENT Item (#PCDATA | Link)*>

<!ELEMENT Link (#PCDATA)>

<!ATTLIST Link

          URL CDATA #REQUIRED>