Flag images originally found at http://www.hahn-hotel.com/flags/
"All sets provided by us are free to use to anyone, for commercial or non-commercial websites."

Later images were found at http://flags.blogpotato.de/ and created by Matthias Slovig
They are under a by-sa-Creative-Commons-License:
http://creativecommons.org/licenses/by-sa/3.0/deed.en_US
Some duplicates of the images have been shaded by the Enigma Team.

