Hey
Well, I finally found someone who knew what it was! This person was in Lindsey's graduating class and knew Lindsey. Here's what he said:
"I knew him very well, the whole family infact. I grew up with him in Atherton and went to school all through up to college. Your question is very easy. The Block Society was the block Menlo-Atherton group for the guys who went out for sports. He played water polo and swam like i did. We all got block letters for a sweater that was worn usually on Fridays."
