Jens,

>> On my passport my name is written "Ka__ebaum" with small letters and >> "KASSEBAUM" with big letters. The reason is that a German "__" doesn't

>> exist as a capital letter.
> 
> You mean "didn't" ;).
> 
> http://en.wikipedia.org/wiki/Capital_%C3%9F

if I may quote the German version 
(http://de.wikipedia.org/wiki/Gro%C3%9Fes_%C3%9F):


"Sie ist nicht Bestandteil der offiziellen deutschen Rechtschreibung."


-- 
Roman