I've heard it defined as either and both ... just as it's being defined here again.
ridelikehell - there's a timeline on the cobratrader.com site that defines S/C as meaning
Semi Competition.
http://www.cobratrader.com/cobrahistory.html - but just because it's written down and put there for everyone to see doesn't make it the definitive truth. Use whichever definition you want.