- "Toggle savehist-mode.
-Positive ARG turns on `savehist-mode'. When on, savehist-mode causes
-minibuffer history to be saved periodically and when exiting Emacs.
-When turned on for the first time in an Emacs session, it causes the
-previous minibuffer history to be loaded from `savehist-file'.
+ "Toggle saving of minibuffer history (Savehist mode).
+With a prefix argument ARG, enable Savehist mode if ARG is
+positive, and disable it otherwise. If called from Lisp, enable
+the mode if ARG is omitted or nil.
+
+When Savehist mode is enabled, minibuffer history is saved
+periodically and when exiting Emacs. When Savehist mode is
+enabled for the first time in an Emacs session, it loads the
+previous minibuffer history from `savehist-file'.