Add warning about exceptions in __del__ being ignored.
diff --git a/Doc/ref3.tex b/Doc/ref3.tex
index e017e26..d1e8b63 100644
--- a/Doc/ref3.tex
+++ b/Doc/ref3.tex
@@ -634,6 +634,10 @@
former decrements the reference count for \code{x} by one, but
\code{x.__del__} is only called when its reference count reaches zero.
+\strong{Warning:} due to the precarious circumstances under which
+\code{__del__} methods are executed, exceptions that occur during
+their execution are \emph{ignored}.
+
\item[{\tt __repr__(self)}]
Called by the \verb@repr()@ built-in function and by string conversions
(reverse or backward quotes) to compute the string representation of an object.