That "15 things never to say to an Autistic" thing was highlee edumacational for me. (My mind went straight to #12, but at least I had enough clue to figure out that if the noun "Autistics" was in the !!title of the posting!! then it was probably OK.)
The one that resonates the most for me is #2 (most of the other entries on the list are just variations of #2, really). I’ve had very kind, very well meaning people say that to me (”I never would have guessed you were autistic!”) in the full belief that they were giving me a compliment, but all it did was make me want to scream, “Yes…and that’s EXACTLY the problem!”
Women and girls on the spectrum are so staggeringly, epidemically underdiagnosed (and present so differently from men and boys) that their symptoms are still invisible to most trained medical doctors, let alone the general public.
No, I don’t present as classically autistic…if your definition of ‘autistic’ comes largely from the movie Rainman. (Which AFAICT portrayed Kanner’s autism, not Asperger’s; there is a vast difference between the two). But the very fact of my ability to “pass” as neurotypical - barely - is the reason why I went undiagnosed for forty years, and why I spent my whole life believing what the uneducated neurotypical people around me told me every day of my life in a million little ways: that I was oversensitive and selfish and wrong and defective.
So when you tell an autistic woman that you’d never guess she was autistic, it’s not so much a compliment to her as it is a condemnation of society’s overwhelming ignorance.
*finishes rant and drags soapbox back into the garage*
(As for “person first” language - I’m not sure I feel all that strongly about it, but my gut feeling is that calling someone “an Autistic” should be treated like a slur reclaimed by a marginalised group: ie, the people within that group can use it, but everyone else should proceed with caution.)