DK8KW wrote :

here in Germany, as soon as you use light for communication, you can only do that with a license !

In that case :
- all traffic lights need a licence (the colour of light tells you wether
you can pass or not ... that's communication)
- all 'neon light ads' in the streets need a licence
- you can only flash your headlights to warn other automobilists if you
have a proper licence
and I'm sure a few dozen more stupid applications can be found.

My suggestion : also allow the use of sound for communication only with a
licence ... that would be 'big bucks' for the governement

73, Rik  ON7YD