There is an interesting point though about what is PC changing over time - and let's simplify the term PC to mean simply what is polite.
Apparently Spastics, no longer the approved term, was a deliberately chosen kinder alternative to "cripple". Similarly you hear Martin Luther King, no less, referring unironically to "the negro" in his speeches, which few of us would feel comfortable with now. I (a white British guy) felt that "people of colour" sounded very wrong, yet it seems the Princess and (black) Americans are perfectly Ok with it, whilst the innocently-meant term "coloured people" of my childhood doesn't sound right to me at all now. An ex-colleague (himself white British) matter of factly refers to his own "mixed race" children, which again wouldn't have been a term I'd have previously used - though it could be that my science sensibility rather than my politics finds "race" a bit of a questionable category in the first place - a bit like the term "reptile" which is basically a nonsense. Hopefully if you try and be polite and respectful you'll not go far wrong regardless of the sanctioned term at any point in time