SET CLEAR determines whether the main FoxPro window is cleared when SET FORMAT is issued.

ON
 If SET CLEAR is ON, the main FoxPro window isn't cleared when you open a format file with SET FORMAT. This is the default setting.

OFF
 The main FoxPro window is cleared if SET CLEAR is OFF.
 
 In FoxPro for MS-DOS, if SET CLEAR is OFF, the main FoxPro window isn't cleared when you exit FoxPro. You can display a sign-off screen when you quit FoxPro.

Other Resources

Backward-Compatible Language Elements