@end defvar
@defvar show-help-function
-@anchor{Help display} If this variable is non-@code{nil}, it specifies a
-function called to display help strings. These may be @code{help-echo}
-properties, menu help strings (@pxref{Simple Menu Items},
-@pxref{Extended Menu Items}), or tool bar help strings (@pxref{Tool
-Bar}). The specified function is called with one argument, the help
-string to display, which is passed through
+@anchor{Help display} If this variable is non-@code{nil}, it specifies
+a function called to display help strings. These may be
+@code{help-echo} properties, menu help strings (@pxref{Simple Menu
+Items}, @pxref{Extended Menu Items}), or tool bar help strings
+(@pxref{Tool Bar}). The specified function is called with one
+argument, the help string to display, which is passed through
@code{substitute-command-keys} before being given to the function; see
-@ref{Keys in Documentation}. Tooltip mode (@pxref{Tooltips,,, emacs,
-The GNU Emacs Manual}) provides an example.
+@ref{Keys in Documentation}. See the code of Tooltip mode
+(@pxref{Tooltips,,, emacs, The GNU Emacs Manual}) for an example of a
+mode that uses @code{show-help-function}.
@end defvar
@defvar face-filters-always-match