You are not allowed to disguise your character using any sort of makeup to change your appearance, since makeup is the only way that players can represent another race or physical characteristics that the players themselves do not have. If you wish to have your character travel incognito, you must use costume and mannerisms.

After all, if there really were elves and orcs and hoblings, you would be able to easily distinguish between a real dark elf and someone disguised as a dark elf, wearing fake ears and face paint.

You are allowed to disguise yourself in limited ways—for example, an elf can wear a hat to hide his ears or a dark elf can wear a hood to cover her face. You can also wear a mask over your face (provided it is a Zorro-type of mask and not a monster mask).