I know I know <raising hand>
It was invented in Level 3.early and was originally intended for remote people running MAS 200 from slow dial-up or ISDN connections, particularly if they ran over a VPN.
Some people called in saying when they were in S/O Entry and clicking on Next number button sometimes resulted in the screen hanging or an Error 14. What happens in MAS is by design the screen loads first and the code behind it loads 2nd. Normally this all happens in a blip and you never notice.
But on a low speed remote connection (or even a medium to high speed connection shared by too many people ergo bandwidth / user severely reduced), the delay between screen load (aka form load) and UI code is more pronounced. IOW the Error 14 when clicking Next # button was cuz they didn't wait another second or 2 after S/O Entry appeared.
So if you turn on Low Speed Connection, now when you open S/O Entry, you see this strange red box appear in front of the screen. To use a geek term it's a modal window but w/o an okay button. It won't let you click anywhere on the S/O Entry screen until the code behind it is fully loaded. Then the strange box goes away.