Update the description of PyTrace_EXCEPT.
diff --git a/Doc/api/init.tex b/Doc/api/init.tex
index 890ca0d..5066c5c 100644
--- a/Doc/api/init.tex
+++ b/Doc/api/init.tex
@@ -708,11 +708,14 @@
\begin{cvardesc}{int}{PyTrace_EXCEPT}
The value of the \var{what} parameter to a \ctype{Py_tracefunc}
- function when an exception has been raised by Python code as the
- result of an operation. The operation may have explictly intended
- to raise the operation (as with a \keyword{raise} statement), or may
- have triggered an exception in the runtime as a result of the
- specific operation.
+ function when an exception has been raised. The callback function
+ is called with this value for \var{what} when after any bytecode is
+ processed after which the exception becomes set within the frame
+ being executed. The effect of this is that as exception propogation
+ causes the Python stack to unwind, the callback is called upon
+ return to each frame as the exception propogates. Only trace
+ functions receives these events; they are not needed by the
+ profiler.
\end{cvardesc}
\begin{cvardesc}{int}{PyTrace_LINE}