[Bug #471893] Replace security material with a warning against unpickling
untrusted data.
diff --git a/Doc/lib/libmarshal.tex b/Doc/lib/libmarshal.tex
index 74770fc..f597e84 100644
--- a/Doc/lib/libmarshal.tex
+++ b/Doc/lib/libmarshal.tex
@@ -26,14 +26,17 @@
Python modules of \file{.pyc} files. Therefore, the Python
maintainers reserve the right to modify the marshal format in backward
incompatible ways should the need arise. If you're serializing and
-de-serializing Python objects, use the \module{pickle} module. There
-may also be unknown security problems with
-\module{marshal}\footnote{As opposed to the known security issues in
-the \module{pickle} module!}.
+de-serializing Python objects, use the \module{pickle} module instead.
\refstmodindex{pickle}
\refstmodindex{shelve}
\obindex{code}
+\begin{notice}[warning]
+The \module{marshal} module is not intended to be secure against
+erroneous or maliciously constructed data. Never unmarshal data
+received from an untrusted or unauthenticated source.
+\end{notice}
+
Not all Python object types are supported; in general, only objects
whose value is independent from a particular invocation of Python can
be written and read by this module. The following types are supported: