Back in the 80s when TSR had a license from Lucasfilm to make Indiana Jones games, they released a game that had a bunch of square cardboard "chits" ... little square tokens with pictures on them. You'd have a chit for Indy, a chit for Sallah, and many chits representing bad guys. At least one of the chits was of a Nazi. Because it was the 80s, everyone was trademark-happy, sticking TM on everything you could, even if it made no sense. If you look at the Marvel Super Heroes game, even in the body text you'd see Spider-Man(TM), Captain America(TM), the Hulk(TM), and so on.
So this Nazi chit had a drawing of a Nazi and the word Nazi. And the word Nazi had a TM and an asterisk on it. The legal line on the chit card (the big square cardboard that you'd pop the chits out of) says [i]"NAZI(TM)*; (TM) & (C) LFL 1984; *trademarks of Lucasfilm, Ltd. used under authorization."[/i]
So the trademark notice was there at the insistence of Lucasfilm. And it's important to point out that the trademark was not for the [b]word[/b] "Nazi" (which is untrademarkable), it was for the [b]specific illustration of that Nazi character[/b].
So TSR never tried to trademark "Nazi."