Looking in the PDGA rules, They don't define what a legal "mini marker disc" is. Can I make my own? Do they need to be a certain size? Seems the smaller the better to keep from touching it when you throw and getting a foot fault. Also they state that any disc that is used during tournament play has to be uniquely marked? My Boss has no stamp or anything left on it, is it illegal? Would ones initials with a sharpie be sufficient? Thanks.