In some German areas you will find that all of the sons had the same first name, frequently Johann, and all of the daughters also, often Anna. You might find a family with Johann Georg, Johann Jacob and Johann Michael. Usually they went by their second name. But when an official record was involved, they might revert to their full name. Hans is a nickname for Johann so you might also find records for Hans Michael or Hans Jacob.
In the Alsace area of France, the administration of the area went back and forth between France and Germany so you may find some records in German and some in French. Johann Jacob or Hans Jacob would become Jean Jacques. Of course, he might also just be Jean (the original Johann given to the whole family) so it is hard to tell which son it could be. Occasionally, names would be reversed so that Michael Georg became Georg Michael, probably because Georg was the name he went by and Michael was only secondary.
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