Offence is so easily given. And where the 'minority' issue is involved, the rules seem to shift about: most of the time a person who is female/black/disabled/gay wants this not to be their defining characteristic; you are supposed to be blind to it. But then, on other occasions, you are supposed to observe special sensitivity, or show special respect.
Talk to the Hand (ed. Penguin, 2005) - ISBN: 9781101216729