diff --git a/doc/execution_context_v2.qbk b/doc/execution_context_v2.qbk
index 9f46aa6..a79c1d2 100644
--- a/doc/execution_context_v2.qbk
+++ b/doc/execution_context_v2.qbk
@@ -297,13 +297,18 @@ exception.
 In this example `f2()` is used to interrupt the `for`-loop in `f1()`.
 
 
-[heading Stack destruction]
+[heading stack unwinding]
 On construction of __econtext__ a stack is allocated.
 If the __context_fn__ returns the stack will be destructed.
 If the __context_fn__ has not yet returned and the destructor of an valid
 __econtext__ instance (e.g. ['execution_context::operator bool()] returns
 `true`) is called, the stack will be destructed too.
 
+[important Code executed by __context_fn__ must not prevent the propagation of the
+__forced_unwind__ exception.  Absorbing that exception will cause stack
+unwinding to fail.  Thus, any code that catches all exceptions must re-throw any
+pending __forced_unwind__ exception.]
+
 
 [#ecv2_prealloc]
 [heading allocating control structures on top of stack]