+{\bf Pay close attention to Step 5.} People often overlook or get
+confused by this powerful feature of the wxWidgets event processing
+system. To put it a different way, events set to propagate
+(\helpref{See: wxEvent::ShouldPropagate}{wxeventshouldpropagate})
+(most likely derived either directly or indirectly from wxCommandEvent)
+will travel up the containment hierarchy from child to parent until the
+maximal propagation level is reached or an event handler is found that
+doesn't call \helpref{event.Skip()}{wxeventskip}.
+
+Finally, there is another additional complication (which, in fact, simplifies
+life of wxWidgets programmers significantly): when propagating the command
+events upwards to the parent window, the event propagation stops when it
+reaches the parent dialog, if any. This means that you don't risk to get
+unexpected events from the dialog controls (which might be left unprocessed by
+the dialog itself because it doesn't care about them) when a modal dialog is
+popped up. The events do propagate beyond the frames, however. The rationale
+for this choice is that there are only a few frames in a typical application
+and their parent-child relation are well understood by the programmer while it
+may be very difficult, if not impossible, to track down all the dialogs which
+may be popped up in a complex program (remember that some are created
+automatically by wxWidgets). If you need to specify a different behaviour for
+some reason, you can use
+\helpref{SetExtraStyle(wxWS\_EX\_BLOCK\_EVENTS)}{wxwindowsetextrastyle}
+explicitly to prevent the events from being propagated beyond the given window
+or unset this flag for the dialogs which have it on by default.
+
+Typically events that deal with a window as a window (size, motion,
+paint, mouse, keyboard, etc.) are sent only to the window. Events
+that have a higher level of meaning and/or are generated by the window
+itself, (button click, menu select, tree expand, etc.) are command
+events and are sent up to the parent to see if it is interested in the
+event.
+