This option is specific to the Windows versions of ACUCOBOL-GT. It affects the way in which updates to a window interact with graphical controls in a window. Normally, Windows allows updates to a parent window to show through any controls in that window. The controls are then updated to create the proper final appearance. This is very fast, but it can cause controls to flash when the background is being updated. When this option is set to 1 (on, true, yes), the controls are clipped from the update region in the parent window before the parent is repainted. This causes the controls to remain relatively stable; however, screen repaints can be significantly slower, particularly when the runtime is creating and destroying controls. The default setting for this option is 0 (off, false, no). We recommend that you experiment with both settings to see which you prefer. Note that this option is examined when a floating window is created. Once a window is created, changes to this option have no effect on that window.