IBM 3270 Manual page 141

If you remove all the windows from a screen
profile, that profile will not appear until you
add windows to it again. The line at the
bottom of the screen will look like this:
WSCTRL WII\JDOW= SCREEN=3
6. When you are ready, press the WSCtrl key to
go back to your work.
You are done.
9-44 Book 3 - Using the Control Program