It goes back to at least Oct 1999 ..

>I think someone at MS does :-)
>
>>Yeah, I got it. I think you've got way too much time on your hands.:-)
>>
>>>>>If you have the July 2000 MSDN (might work with others), launch it and in the Index search field, type "Shell." (note the period) and press Enter. What do you see?
>>>>
>>>>I'm running October, 2000. I see 500 matches. What are you seeing?