-Optional third arg ALL-FRAMES t means include windows on all frames.
-ALL-FRAMES nil or omitted means cycle within the frames as specified
-above. ALL-FRAMES = `visible' means include windows on all visible frames.
-ALL-FRAMES = 0 means include windows on all visible and iconified frames.
-If ALL-FRAMES is a frame, restrict search to windows on that frame.
-Anything else means restrict to WINDOW's frame.
-
-Optional fourth arg CONSOLE controls which consoles or devices the
-returned window may be on. If CONSOLE is a console, return windows only
-on that console. If CONSOLE is a device, return windows only on that
-device. If CONSOLE is a console type, return windows only on consoles
-of that type. If CONSOLE is 'window-system, return any windows on any
-window-system consoles. If CONSOLE is nil or omitted, return windows only
-on WINDOW's console. Otherwise, all windows are considered.
-
-If you use consistent values for MINIBUF, ALL-FRAMES, and CONSOLE, you
-can use `previous-window' to iterate through the entire cycle of acceptable
-windows, eventually ending up back at the window you started with.
+By default, only the windows in the selected frame are considered.
+The optional argument WHICH-FRAMES changes this behavior:
+WHICH-FRAMES = `visible' means search windows on all visible frames.
+WHICH-FRAMES = 0 means search windows on all visible and iconified frames.
+WHICH-FRAMES = t means search windows on all frames including invisible frames.
+WHICH-FRAMES = a frame means search only windows on that frame.
+Anything else means restrict to the selected frame.
+
+The optional fourth argument WHICH-DEVICES further clarifies on which
+devices to search for frames as specified by WHICH-FRAMES. This value
+is only meaningful if WHICH-FRAMES is non-nil.
+If nil or omitted, search all devices on the selected console.
+If a device, only search that device.
+If a console, search all devices on that console.
+If a device type, search all devices of that type.
+If `window-system', search all window-system devices.
+Any other non-nil value means search all devices.
+
+If you use consistent values for MINIBUF, WHICH-FRAMES, and WHICH-DEVICES,
+you can use `previous-window' to iterate through the entire cycle of
+acceptable windows, eventually ending up back at the window you started with.