One of the most obvious features on Ace is his tattoos. Ace's back tattoo is left intact in the English version of the dub despite 4Kids' previous edits to crosses. At the same time Ace also promotes his tattoo to Luffy, something which is truly considered odd by 4Kids standards. Ace has a tattoo on his back of the Whitebeard symbol; a skull with a white mustache and a manji behind it. To avoid confusion between the two symbols and avoid slander for being a nazi, this was changed to crossbones in the shape of a "cross" in the anime, as well as in the most recent chapter of the manga.
Ace has another tattoo on his left arm by the shoulder: it reads "ASCE" with the "S" (apparently a mistake on the part of the tattoo artist, or, alternatively, the symbol that appeared on the flag of his old crew развернуть