sacs or sacks?

It has come to my attention the the Student Congress Assembly logo has an extra 'S' at the end of it. When I asked what this means and am startled by my answer. (if you want to know the answer as me in person, I have a feeling I'll get thrown off of blogger and Pocketlint will strangle me.)
Oh, and I just wanted to put this on here because it bothers Emma, teHEHEHE!