According to Sutherlands, the fixed cup on 8-sided fixed cups have one groove (or ring) for French, but NO grooves (rings) for Swiss.
Sutherlands also say that the adjustable cup for French is 6-sided and has no rings...presumedly that's the same for Swiss, it's also the same for British adj. cups, but the FR lockring has 6 notches while the BSC has 4 or 8.
confused yet?