Hose nipple

[gregsj@minimall.imm.com]

Fellow Audians; I popped the hood on my 91' 200TQW to show a friend what 
technology looks like. He noticed a hose nipple that had no hose. Being 
naturally curious, I was wondering what it was. As you face the car (head-on); 
I'm assuming that the very obvious circular device that resides between the 
black airbox (on its left) and the 20 valve, valve covers (on its right) is the 
turbo bypass valve (OK, so I'm not a gear head - I had enough sense to buy an 
Audi didn't I?). At 12:00 on this bypass valve is a hose-less nipple. Are we 
missing a hose, or is this a place for a mechanic to plug into or something? 
Many thanks. Greg