Lots of markup cleanups to avoid warnings from the GNU info generation;
these make sense even without that processing chain.
diff --git a/Doc/lib/librfc822.tex b/Doc/lib/librfc822.tex
index e8cad19..e32493c 100644
--- a/Doc/lib/librfc822.tex
+++ b/Doc/lib/librfc822.tex
@@ -255,10 +255,10 @@
In particular: \code{\var{m}[name]} is like
\code{\var{m}.getheader(name)} but raises \exception{KeyError} if
there is no matching header; and \code{len(\var{m})},
-\code{\var{m}.get(\var{name}\optional{\var{, default}})},
+\code{\var{m}.get(\var{name}\optional{, \var{default}})},
\code{\var{m}.has_key(\var{name})}, \code{\var{m}.keys()},
\code{\var{m}.values()} \code{\var{m}.items()}, and
-\code{\var{m}.setdefault(\var{name}\optional{\var{, default}})} act as
+\code{\var{m}.setdefault(\var{name}\optional{, \var{default}})} act as
expected, with the one difference that \method{setdefault()} uses
an empty string as the default value. \class{Message} instances
also support the mapping writable interface \code{\var{m}[name] =