Lots of explicit class names for method and member descs.
diff --git a/Doc/lib/libmailbox.tex b/Doc/lib/libmailbox.tex
index 7c716b7..c3e7ffd 100644
--- a/Doc/lib/libmailbox.tex
+++ b/Doc/lib/libmailbox.tex
@@ -1246,7 +1246,7 @@
Older mailbox objects support only iteration and provide a single public
method:
-\begin{methoddesc}{next}{}
+\begin{methoddesc}[oldmailbox]{next}{}
Return the next message in the mailbox, created with the optional \var{factory}
argument passed into the mailbox object's constructor. By default this is an
\class{rfc822.Message} object (see the \refmodule{rfc822} module). Depending