;;;###autoload
(defun dired-do-chmod (&optional arg)
"Change the mode of the marked (or next ARG) files.
-Symbolic modes like `g+w' are allowed.
-Type M-n to pull the file attributes of the file at point
-into the minibuffer."
+Both octal numeric modes like `644' and symbolic modes like `g+w'
+are supported. Type M-n to pull the file attributes of the file
+at point into the minibuffer.
+
+See Info node `(coreutils)File permissions' for more information.
+Alternatively, see the man page for \"chmod\", using the command
+\\[man] in Emacs.
+
+Note that on MS-Windows only the `w' (write) bit is meaningful:
+resetting it makes the file read-only. Changing any other bit
+has no effect on MS-Windows."
(interactive "P")
(let* ((files (dired-get-marked-files t arg nil nil t))
;; The source of default file attributes is the file at point.