added classes as exceptions
diff --git a/Doc/ref/ref6.tex b/Doc/ref/ref6.tex
index 70e1a68..f0f318f 100644
--- a/Doc/ref/ref6.tex
+++ b/Doc/ref/ref6.tex
@@ -324,13 +324,20 @@
\end{verbatim}
\verb@raise@ evaluates its first condition, which must yield
-a string object. If there is a second condition, this is evaluated,
-else \verb@None@ is substituted.
+a string, class, or instance object. If there is a second condition,
+this is evaluated, else \verb@None@ is substituted. If the first
+condition is a class object, then the second condition must be an
+instance of that class or one of its derivatives. If the first
+condition is an instance object, the second condition must be
+\verb@None@.
\index{exception}
\indexii{raising}{exception}
-It then raises the exception identified by the first object,
-with the second one (or \verb@None@) as its parameter.
+If the first object is a class or string, it then raises the exception
+identified by the first object, with the second one (or \verb@None@)
+as its parameter. If the first object is an instance, it raises the
+exception identified by the class of the object, with the instance as
+its parameter.
\section{The {\tt break} statement}
\stindex{break}