Subwindow is the name given to ACUCOBOL-GT text-mode windows created with the DISPLAY WINDOW or DISPLAY SUBWINDOW statement. Prior to Version 3.0 these windows were simply referred to as windows.
Subwindows are always text-mode windows and are not compatible with graphical controls. However, subwindows can be mixed with floating windows, so long as the subwindows do not display on top of graphical controls. When an overlay occurs, due to the workings of the underlying host system, control objects are improperly displayed on top of the text-mode subwindow. For a discussion of textual and graphical modes, see Chapter 4, section 4.3.
You can easily convert subwindows to floating windows by changing the DISPLAY WINDOW statement to a DISPLAY FLOATING WINDOW statement. However, subwindows that simply define a screen region, that are not bordered, or are not pop-up in nature, do not lend themselves to conversion to floating windows.