What makes 'cos' unique?

Note: the category and title are both clues and you may need to use some twisted logic as the answer is not straightforward

I haven't looked at any comment since my last, except the hint... So what is unique about c, o, and s? Each one has nothing but curves in its shape! There aren't any other letters like that, as long as you strictly only include letters with no straight parts. Anything else special? I don't know.

Posted by Tristan on 2003-09-22 19:44:11