Comments produce X·M·L comment nodes and can be used to break up list
items into separate lists.
-- If the paragraph begins with `⋯`, it is a continuation paragraph
- (`<html:div class="continuation">`).
+- If the paragraph begins with `⋯`, it is a continuation paragraph.
Continuation paragraphs may be used to continue a preceding div or
list item.
+ If there is no such preceding div or list item, they will attach to
+ adjacent heading elements to form heading groups (`<html:hgroup>`).
+ Otherwise, they will be treated as ordinary paragraphs.
- Otherwise, it is an ordinary paragraph.