Hi Scott,
>The Franz (or Fritz) ...
Unfortunately, "Franz" - while often used by the online community - is in a fact a fantasy designation.
It's really "Friedrich", for the letter "F" in the German phonetic alphabet. The name "Friedrich" often is abbreviated to "Fritz" (as you quoted, too).
("Franz" of course has no phonetic value, too easy to confuse with "Hans"!)
The phonetic alphabet goes "Anton, Berta, Cäsar, Dora, Emil, Friedrich, Gustav, ..." - I'm sure you recognize a few of the other codes as well :-)
(It's similar to the old Able, Baker, Charlie, Dog, ... alphabet used by the USAAF and later the USAF - some authors speculate about the F-86D named "Sabre Dog" for its radar nose, but of course, it's was simply named for its phonetic code :-)
Regards,
Henning (HoHun)