I don't know if your question has been answered by A. Kandaurov on his site http://shashki.com
If it is just a coincidence - he refer to chess site http://www.sahovski.co.yu/other/index.php?other=6
Some of this signs are being used in draughts as well.
? ! and all its combinations, +-, ++, =
About complete system I've never heard. Only about intention of its creation. I can remember one Israelian draughtsman began to make some kind of draughts dictionary. But he never ended it. Would be nice if someone shows us a better ( draughts ) link.