Appendix talk:German spelling alphabet
Cf. https://de.wikipedia.org/wiki/Buchstabiertafel
i believe the most common contemporary usage is DIN 5009, with Kaufmann (not Kurfürst), with Zacharias (not Zeppelin), and with Xanthippe (not Xaver). Note that many younger Germans may not know "Eszett", so I recommend writing "Eszett (also: scharfes S)". "Siegfried" might be more in use than "Samuel", possibly because it is a more common name. Note the history of this: https://de.wikipedia.org/wiki/Buchstabiertafel#Geschichte . I recommend that you write "Samuel (also: Siegfried)".
(And obviously, DIN 5009 is used most often since Germany has more inhabitants than Austria or Switzerland.)
I don't think the massive disclaimer on top is necessary. Rather, put it into the discussion, i.e., here.
(Sources: I'm a native speaker from Germany.)
EDIT: I have now implemented all of these points. I have checked the German Wikipedia page http://de.wikipedia.org/wiki/Buchstabiertafel which in my opinion IS a reliable source, unlike the claims of the person who added the following cleanup proposal. So I have now removed the following text:
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