Updates to the exceptions documentation (this is my patch #1156102).

1 files changed, 14 insertions, 10 deletions

diff --git a/Doc/ref/ref4.tex b/Doc/ref/ref4.tex
index dbd6a2f..6a3a4ef 100644
--- a/Doc/ref/ref4.tex
+++ b/Doc/ref/ref4.tex
@@ -182,16 +182,20 @@ either case, it prints a stack backtrace, except when the exception is
 \exception{SystemExit}\withsubitem{(built-in
 exception)}{\ttindex{SystemExit}}.
 
-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
-as the exception's \emph{value}; this object does not affect the
-selection of an exception handler, but is passed to the selected
-exception handler as additional information.  For class exceptions,
-this object must be an instance of the exception class being raised.
+Exceptions are identified by class instances.  The \keyword{except}
+clause is selected depending on the class of the instance: it must
+reference the class of the instance or a base class thereof.  The
+instance can be received by the handler and can carry additional
+information about the exceptional condition.
+
+Exceptions can also be identified by strings, in which case the
+\keyword{except} clause is selected by object identity.  An arbitrary
+value can be raised along with the identifying string which can be
+passed to the handler.
+
+\deprecated{2.5}{String exceptions should not be used in new code.
+They will not be supported in a future version of Python.  Old code
+should be rewritten to use class exceptions instead.}
 
 \begin{notice}[warning]
 Messages to exceptions are not part of the Python API.  Their contents may