Ok, it is that circle (filled or not) with 8 arrows coming out of it, usually stylized. It was designed by Michael Moorcock, but other people appear to be using it everywhere. In particular, I've seen it in Hexen video game. Can we use it in our games or it will get us in trouble, just like using the Beholder monster? Or maybe it is a basic geometric figure, that can not be copyrighted or trademarked?