-(defvar ido-all-frames 'visible
- "*Argument to pass to `walk-windows' when finding visible files.
-See documentation of `walk-windows' for useful values.")
+(defcustom ido-all-frames 'visible
+ "Argument to pass to `walk-windows' when Ido is finding buffers.
+See documentation of `walk-windows' for useful values."
+ :type '(choice (const :tag "Selected frame only" nil)
+ (const :tag "All existing frames" t)
+ (const :tag "All visible frames" visible)
+ (const :tag "All frames on this terminal" 0))
+ :group 'ido)