Oh, sorry. The German subject names are confusing to me. :S (In Japanese, it's just 1A, 1B, 2A, 2B..)
In Japanese, they also have it where multiple codes correspond to the same subject (110-142, 110-280, 110-354). The email response I got was "There are 3 levels within J1B. Which one to choose? My understanding is if you are 1st yr student, then take level 1 (110142), 2nd yr, level 2, and the rest, level 3. However, I suggest you should go to your student centre to clarify this." However, there's this kind of warning thing on lms. "Students should be aware that there is a Faculty policy on marks for first, second and third year subjects. Students should note that it may be necessary to scale marks in some subjects at the end of semester to comply with Faculty requirements." I have no idea what it means. So maybe the content is the same, but they scale it differently in the end? Not too sure..
EDIT: Yep, you should enrol in 670-231, then.