diff --git a/doc/emacs/custom.texi b/doc/emacs/custom.texi
index 86e27b64243..59cd57b1e6c 100644
--- a/doc/emacs/custom.texi
+++ b/doc/emacs/custom.texi
@@ -1417,6 +1417,14 @@ commands, and @dfn{keymaps}, which record key bindings.  It also
 explains how to customize key bindings, which is done by editing your
 init file (@pxref{Init Rebinding}).
 
+  Since most modes define their own key bindings, activating a mode
+might override your custom key bindings.  A small number of keys are
+reserved for user-defined bindings, and should not be used by modes,
+so key bindings using those keys are safer in this regard.  The
+reserved key sequences are those consisting of @kbd{C-c} followed by a
+letter (either upper or lower case), and function keys @key{F5}
+through @key{F9} without modifiers (@pxref{Modifier Keys}).
+
 @menu
 * Keymaps::             Generalities.  The global keymap.
 * Prefix Keymaps::      Keymaps for prefix keys.
diff --git a/doc/emacs/xresources.texi b/doc/emacs/xresources.texi
index a0de3134db7..096e747a044 100644
--- a/doc/emacs/xresources.texi
+++ b/doc/emacs/xresources.texi
@@ -221,7 +221,7 @@ Additional space between lines, in pixels.
 @cindex background for menus
 The background color of the menus in non-toolkit versions of Emacs.
 (For toolkit versions, see @ref{Lucid Resources}, also see @ref{Motif
-Resources}, and see @ref{GTK Resources}.)
+Resources}, and see @ref{GTK resources}.)
 @end ifnottex
 
 @item @code{menuBar} (class @code{MenuBar})
@@ -238,13 +238,13 @@ will use a separate minibuffer frame instead.
 @cindex font for menus
 Font name for menu pane titles, in non-toolkit versions of Emacs.
 (For toolkit versions, see @ref{Lucid Resources}, also see @ref{Motif
-Resources}, and see @ref{GTK Resources}.)
+Resources}, and see @ref{GTK resources}.)
 
 @item @code{paneForeground} (class @code{Foreground})
 @cindex foreground for menus
 Foreground color for menu pane titles, in non-toolkit versions of
 Emacs.  (For toolkit versions, see @ref{Lucid Resources}, also see
-@ref{Motif Resources}, and see @ref{GTK Resources}.)
+@ref{Motif Resources}, and see @ref{GTK resources}.)
 @end ifnottex
 
 @item @code{pointerColor} (class @code{Foreground})
@@ -282,12 +282,12 @@ compiled with GTK+ support.
 @item @code{selectionFont} (class @code{SelectionFont})
 Font name for pop-up menu items, in non-toolkit versions of Emacs.  (For
 toolkit versions, see @ref{Lucid Resources}, also see @ref{Motif
-Resources}, and see @ref{GTK Resources}.)
+Resources}, and see @ref{GTK resources}.)
 
 @item @code{selectionForeground} (class @code{SelectionForeground})
 Foreground color for pop-up menu items, in non-toolkit versions of
 Emacs.  (For toolkit versions, see @ref{Lucid Resources}, also see
-@ref{Motif Resources}, and see @ref{GTK Resources}.)
+@ref{Motif Resources}, and see @ref{GTK resources}.)
 
 @item @code{selectionTimeout} (class @code{SelectionTimeout})
 Number of milliseconds to wait for a selection reply.