For a top-level CWnd object, the x and y parameters are relative to the upper-left corner of the screen. For a child CWnd object, they are relative to the upper-left corner of the parent window's client area.

The MoveWindow function sends the WM_GETMINMAXINFO message. Handling this message gives CWnd the opportunity to modify the default values for the largest and smallest possible windows. If the parameters to the MoveWindow member function exceed these values, the values can be replaced by the minimum or maximum values in the WM_GETMINMAXINFO handler.