Curiously, the hooked cross (hakenkreuz, swastika, flyfot) shows up in lots of
places with lots of orientations. As noted, it's everything from an ancient art
symbol found on pottery and the like to brief usage in the Finnish Air Force.
One use I've seen is on Japanese/English roadmaps, used to denote Buddhist
Temples. There, it's the reverse of the Finnish use (i.e., the maps have bent
arms vertical/horizontal, but bent counter-clockwise).
Also, as noted, color aircraft pictures show the Finnish symbol in light
blue on a white circle; Nazi swastikas appear to be tail-only, black, possibly
bordered white, rotated 1/8 of the way from vertical/horizontal.
As noted, symbolism is strong. I suspect, though, that German law doesn't
stretch all the way to Finnish aircraft or Japanese/English map icons or
ancient pottery.
-- Dennis S, FSEngEd@aol.com