--- src/xdisp.c.orig	Thu Dec  6 10:38:25 2001
+++ src/xdisp.c	Thu Dec  6 10:43:02 2001
@@ -14808,7 +14808,10 @@
 \(Assuming the window manager supports this feature.)\n\
 This variable has the same structure as `mode-line-format' (which see),\n\
 and is used only on frames for which no explicit name has been set\n\
-\(see `modify-frame-parameters').");
+\(see `modify-frame-parameters').\n\
+Note that the frame title is updated only in special situations,\n\
+as an efficiency measure.");
+
   DEFVAR_LISP ("icon-title-format", &Vicon_title_format,
     "Template for displaying the title bar of an iconified frame.\n\
 \(Assuming the window manager supports this feature.)\n\