And all these years I thought its purpose was to prevent the screen/window/application from scrolling.
No that's the Pause key. Go to a cmd window and type dir %tmp% and try it. Ctrl-S does the same thing.
Leveraging my DOS 2 skills is the reason I will never be a Mac user. Usually I say that seriously, in this case, not so much because I don't actually use that anymore. I just do something like
and it pops up in Notepad. Redirection of course is also a leveraged DOS 2 skill. (yeah I know they stole it from CP/M and Unix)