Thanks for the replies. It was not two-way or double barreled stayman. It might have been the viking precision system; I used to own the viking precision book a few years back so it might have been there I came across it. Unfortunately, I lost the book so I cant check. I didnt use the system for very long but my initial impression (we used a weak 1NT opening) was that the decision between playing 3NT-4M or 3NT-5m became easier. Also, the decision between 5m or 6m became easier. Giving this information away to the opponents is of course not good, but I still found the system good against the opponents I faced.