SRK got a TATTOO for RaONE

Shah Rukh Khan was spotted at the airport while enroute to Singapore for an awards gala,

with what appeared like a tattoo with the alphabet D on his arm.

Has King Khan got himself inked or is it a temporary inking?

And does 'D' stand for Don (his forthcoming flick) or is it for Ra.One?

Or for one of his endorsment deals?