SF bug #719367, string exceptions are deprecated
Remove references to string based exceptions in the doc.
diff --git a/Doc/ref/ref4.tex b/Doc/ref/ref4.tex
index 0eb6841..b993266 100644
--- a/Doc/ref/ref4.tex
+++ b/Doc/ref/ref4.tex
@@ -183,12 +183,9 @@
\exception{SystemExit}\withsubitem{(built-in
exception)}{\ttindex{SystemExit}}.
-Exceptions are identified by string objects or class instances.
-Selection of a matching except clause is based on object identity
-(i.e., two different string objects with the same value represent
-different exceptions!) For string exceptions, the \keyword{except}
-clause must reference the same string object. For class exceptions,
-the \keyword{except} clause must reference the same class or a base
+Exceptions are identified by class instances.
+Selection of a matching except clause is based on object identity.
+The \keyword{except} clause must reference the same class or a base
class of it.
When an exception is raised, an object (maybe \code{None}) is passed
diff --git a/Doc/ref/ref6.tex b/Doc/ref/ref6.tex
index d447f24..a078aa4 100644
--- a/Doc/ref/ref6.tex
+++ b/Doc/ref/ref6.tex
@@ -521,9 +521,8 @@
\end{productionlist}
If no expressions are present, \keyword{raise} re-raises the last
-expression that was active in the current scope. If no exception has
-been active in the current scope, an exception is raised that
-indicates indicates that this is the error.
+expression that was active in the current scope. If no exception is
+active in the current scope, an exception is raised indicating this error.
\index{exception}
\indexii{raising}{exception}
@@ -545,9 +544,6 @@
constructor. The instance so created by calling the constructor is
used as the exception value.
-If the first object is a string, the string object is the exception
-type, and the second object becomes the exception value.
-
If a third object is present and not \code{None}, it must be a
traceback\obindex{traceback} object (see section~\ref{traceback}), and
it is substituted instead of the current location as the place where