- "Toggle display of European characters encoded with ISO 8859.
-When enabled, characters in the range of 160 to 255 display not
-as octal escapes, but as accented characters.
-With prefix argument, enable European character display iff arg is positive."
- (interactive "P")
+ "Semi-obsolete way to toggle display of ISO 8859 European characters.
+
+This function is semi-obsolete; if you want to do your editing with
+unibyte characters, it is better to `set-language-environment' coupled
+with either the `--unibyte' option or the EMACS_UNIBYTE environment
+variable, or else customize `enable-multibyte-characters'.
+
+With prefix argument, this command enables European character display
+if arg is positive, disables it otherwise. Otherwise, it toggles
+European character display.
+
+When this mode is enabled, characters in the range of 160 to 255
+display not as octal escapes, but as accented characters. Codes 146
+and 160 display as apostrophe and space, even though they are not the
+ASCII codes for apostrophe and space.
+
+Enabling European character display with this command noninteractively
+from Lisp code also selects Latin-1 as the language environment, and
+selects unibyte mode for all Emacs buffers \(both existing buffers and
+those created subsequently). This provides increased compatibility
+for users who call this function in `.emacs'."
+