+<!ELEMENT puzzle ( %inline.content; | %mixed.content; )*>
+<!ATTLIST puzzle
+ %core.attributes;
+ %link.attributes;
+ idrefs IDREFS #IMPLIED
+>
+<!--
+
+The "puzzle" element contains the text describing the action of
+proceeding to the section that is the answer for a puzzle or riddle
+presented elsewhere within the section. It's a linking element and
+therefore can link to the place to which the correct answer to the
+puzzle leads. In the case that the puzzle has multiple solutions, use a
+space separated list of IDs in the "idrefs" attribute. This link
+information should not generally be presented to the reader.
+
+Examples:
+
+ <section id="section12" . . .> . . . </section>
+ . . .
+ <puzzle idref="section12">If you know the answer to her riddle, turn to
+ the entry of that number.</puzzle>
+
+
+ <section id="section23" . . .> . . . </section>
+ . . .
+ <section id="section350" . . .> . . . </section>
+ . . .
+ <puzzle idrefs="section23 section350">If you know only one of the two
+ correct numbers that you need to open the lock, turn to the entry of
+ that number.</puzzle>
+
+-->
+
+<!ELEMENT deadend ( %inline.content; | %mixed.content; )*>
+<!ATTLIST deadend
+ %core.attributes;
+>
+<!--
+
+The "deadend" element contains the text describing the fact that an
+adventure has come to an end (e.g. the character has died).
+
+Example:
+
+ <deadend>Tragically, your life ends here.</deadend>
+
+-->
+