Go to this forum to look at the old German alphabet. Notice the "missing" letters. No one needed to tell anyone to "skip" the J; it wasn't there.
http://www.mun.ca/rels/morav/pics/tutor/mscript2.html
There is a further explanation at this location:
http://members.cox.net/leshopper/exprgesc.pdf
Note the paragraph about the alphabet reforms in the 1930's under Hitler, when J was officially made part of the alphabet just in time to be used on some late Lugers and P.38's. Now does anyone want to ask why they "skipped" the Y also? Or why the English alphabet "skips" Cyrillic letters?
Jim