A = negation of T = theism O = horizontal equality
This symbol is nicknamed A/T.
More tha 80 official languages and many dialects use the letters A+T as the root letters of the word ATheist.
Look at this multilingual slide-show to find your language:
The discussion is open now:
"DO WE NEED AN UNIVERSAL ATHEIST SYMBOL".
Many grupos and individuals have already adopted the one I am proposing here.
Please be open minded and exercise your free thought :-)
And do not think of this symbol as opposed to the religious symbols it is more close to de PEACE (hippy) symbol and the utopian ANARCHIST one.
The scarlet 'A' is my favourite.