There is only one level of paragraph quoting; quoted paragraphs may
not be quoted again.
+- If every line in the paragraph begins with zero or more white·space
+ characters followed by `|`, it is a “preformatted” paragraph and
+ white·space is not collapsed (`<html:pre>`).
+ A paragraph may be both quoted and preformatted.
+
- Otherwise, the paragraph is unquoted.
After this classification, each quoted or unquoted paragraph is further
classified by type based on its first character (which is must be
- followed by white·space to be recognized) :—
+ followed by white·space, or else the only thing on the line) :—
+
+- If the paragraph is preformatted, it is an ordinary paragraph.
- If the paragraph begins with `⁌`, it is a chapter heading
(`<html:h1>`).
- Successive list items of the same level and class are joined into
a single list.
+- Linebreaks in preformatted paragraphs are replaced with `<html:br>`.
+
Finally, any character can be escaped by instead providing its Unicode
codepoint in the form `<U+NNNN>`, where `NNNN` is one or more
hexadecimal digits.