An acronym that stands for "That Asshole Nobody Talks About" usually meant to refer to a person who did something incredibly shitty or horrible and is no longer mentioned by others who knew and associated with them, effectively making them an outcast. Usually if a TANTO's name is mentioned, others will respond with simple quotes such as "We don't talk about them..."
Person 1: Why hasn't Mike come to any of our club meetings anymore?
Person 2: He's a T.A.N.T.A., we don't talk about him anymore
Person 1: Why, what did he...
Person 2: *glares* WE DON'T...TALK ABOUT HIM...ANYMORE...
Person 1: Okay O_O
D.A.N. (pronounced like the Englishname, 'Dan,' short for 'Daniel') is an acronym for <b>D</b>umb <b>A</b>ss <b>N</b>igger. Typically used as a disguised racial epithet when addressing a dark-skinned person of color.
One of my coworkers keep addressing me as, "Dan" or is it "D.A.N.", even though I've told him my name was Tony. What gives?