<!ENTITY % attrs
 "key ID #IMPLIED
  man CDATA #IMPLIED"
>

<!ENTITY % heading
 "key ID #IMPLIED
  man CDATA #IMPLIED
  img CDATA #IMPLIED
  title CDATA #REQUIRED"
>

<!ENTITY % content
 "p | img | dl | ul | table | tabular | matrix | shortcut | verbatim"
>

<!ENTITY % format
 "a | ref | ndash | q | cmd | file | gui | emph"
>

<!-- root element -->

<!ELEMENT aqualung-doc (titlepage,document)>

<!-- titlepage -->

<!ELEMENT titlepage (title,copyright,license)>
<!ELEMENT title (#PCDATA)>
<!ELEMENT copyright (#PCDATA)>
<!ELEMENT license (#PCDATA | br)* >

<!-- document parts -->

<!ELEMENT document (section)+>

<!ELEMENT section (subsection|%content;)+>
<!ATTLIST section %heading;>

<!ELEMENT subsection (subsubsection|%content;)+>
<!ATTLIST subsection %heading;>

<!ELEMENT subsubsection (paragraph|%content;)+>
<!ATTLIST subsubsection %heading;>

<!ELEMENT paragraph (%content;)+>
<!ATTLIST paragraph %heading;>

<!-- paragraph -->

<!ELEMENT p (#PCDATA|%format;)*>
<!ATTLIST p %attrs;>

<!-- line break -->

<!ELEMENT br EMPTY>

<!-- unnumbered list -->

<!ELEMENT ul (li)+>
<!ATTLIST ul %attrs;>

<!ELEMENT li (#PCDATA|%format;)*>
<!ATTLIST li %attrs;>

<!-- definition list -->

<!ELEMENT dl (dt|dd)+>
<!ATTLIST dl %attrs;>

<!ELEMENT dt (#PCDATA|%format;)*>
<!ATTLIST dt %attrs;>

<!ELEMENT dd (#PCDATA|%format;)*>
<!ATTLIST dd %attrs;>

<!-- image -->

<!ELEMENT img EMPTY>
<!ATTLIST img
 src CDATA #REQUIRED
 alt CDATA #REQUIRED
>

<!-- table -->

<!ELEMENT table (tr)+>
<!ATTLIST table %attrs;>

<!ELEMENT tabular (tr)+>
<!ATTLIST tabular %attrs;>

<!ELEMENT matrix (tr)+>
<!ATTLIST matrix %attrs;>

<!ELEMENT shortcut (tr|hline)+>
<!ATTLIST shortcut %attrs;>

<!ELEMENT tr (td)+>

<!ELEMENT td (#PCDATA|%format;)*>

<!-- verbatim text -->

<!ELEMENT verbatim (#PCDATA)>

<!-- horizontal line -->

<!ELEMENT hline EMPTY>

<!-- link -->

<!ELEMENT a (#PCDATA)>
<!ATTLIST a href CDATA #REQUIRED>

<!-- cross reference -->

<!ELEMENT ref (#PCDATA|%format;)*>
<!ATTLIST ref refkey IDREF #REQUIRED>

<!-- format -->

<!ELEMENT q (#PCDATA|%format;)*>
<!ELEMENT cmd (#PCDATA|%format;)*>
<!ELEMENT emph (#PCDATA|%format;)*>
<!ELEMENT file (#PCDATA)>
<!ELEMENT gui (#PCDATA)>

<!-- entity -->

<!ELEMENT ndash EMPTY>