This article is from the German Genealogy FAQ, by Jim Eggert EggertJ@crosswinds.net with numerous contributions by others.
Different areas/times/families had different naming conventions.
No general rule applies in every case. Babies are often named
for family members or baptismal sponsors, and sometimes a pattern
can be found.
Often a person does not go by his first given name, especially
if that first name is Johann or Maria. The name actually used
(termed the Rufname) is often denoted by an asterisk or by
underlining.
 
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