Seriously guys? (PFL)

There is no general consensus on how to describe autistic people/people with autism/autism spectrum folk, though surveys suggest that "autistic person" is preferred by a large majority. Understanding this is step one. Step two is realizing that we live in a society that is really bad about giving people with disabilities any sort of self determination at all, especially people whose disabilities are developmental. Autism is one of these. That means autistic people are going to be extremely touchy about anything that even smells like taking away self-determination, and not respecting language choices is one of those things. We have our reasons. And guess what? The more someone has had self-determination taken away from them, the more likely they are to be on guard if someone tries it again. That means that some people are going to care more than others. So how do you get it right?

1. If the fact that we are autistic is not relevant to the topic at hand, we might not want it mentioned at all. Respect that. We have the right to at least TRY to pass if we so choose. And you'd be surprised how much can pass for ``just weird," especially if you have enough other privileges or enough autism stereotypes that you break. On top of that, I'm fairly sure that only the autistic person themself can legally disclose unless they are a) a minor, in which case their guardian can, but really should listen to the persons wishes on this or b) the person/their guardian has given you permission to do so.
2. Many autism organizations (looking at you, Autism Speaks. I know for a fact that you do this) will insist on person first language. That's calling people ``people with autism" instead of ``autistic people." That's actually the norm for the disability rights movement, but within autism specifically, there is not a consensus on person first language. The majority of the actually autistic seem to prefer NOT person first language. And you should respect that. You should also respect those people who do prefer person first.
3. If someone tells you their preference, they do not also have to tell you why. You just have to go with it. (They can tell you if they want to, which is different from "if you are really really curious.")
4. Fourth thing: Some people just aren't going to care which you use. It probably won't happen that often, but in that case, it really doesn't matter. In that case, go with whatever the majority of autistic people in your audience prefer, followed by audience in general if there is a tie. (On the internet, that large majority of autistic people who prefer autistic person are the audience autistic majority.)
5. Fifth thing: The opinion of the autistic person you are speaking about overrides ALL other opinions in how they should be described. Period.