We've had the mandatory service charge added at restaurants on both the dutch and french sides. Some of them; not all of them. At Chesterfield's, for example it was written directly on our check. At this place we pay in U.S. funds, so if the service was good I automatically add another 10% to the ten percent service charge to even things out. So, you kind of have to look for this on your bill.

On the french side, some (not all) of the restaurants pre-print the higher rate on the menu if paying in U.S. funds. I think the last time we ate at the Rainbow Cafe it stated 1.10-to-1 if paying in U.S. dollars. Or, something like that. If the service is good we'll typically round up the bill whether paying in either euros or dollars, and if the service was out standing (like the last time we dined at Ocean 82) the waiter was so awesome that I did tip the guy another 20 percent.

Hopefully, this doesn't confuse anyone further! Just watch for the service charge and ask about it if you must. Then, calculate your tip accordingly if one is present.