E.g. fandom nattering that uses "-coded" to describe a character they think is autistic but the creator won't state it. It's just young people shortening "seems like he's written as."
"-Jacketed," however: big warning sign.
I have a theory that many writers don't really believe in autism an objective diagnosis subconsciously, just like how they subconsciously don't believe that trans women are women. they might see being socially awkward etc. is a trait that any human can have. 'coding', while it can be a real thing from writers, is oftentimes just a projection from the fans who want the characters to be 'officially' autistic.
A lot of people have noted before that a lot of modern malaise don't get portrayed in fiction that much, we don't portray people swiping on Tinder or doomscroll Tiktok or trying to make millions from crypto or AI generated content farm slop. When a piece of media try to portray today's world, it comes across as ridiculous - think of Adolescent, that show about incel murderer kid, and how it's no longer talked about soon after the hype died down because people realised it's another government-sponsored moral panic piece that bong TV likes to do. Many people, including writers, subconsciously know that the way we live today is soulless and cannot be depicted accurately anymore in fiction without it looking stupid. That's why there's a lot 'period piece of the recent past' setting in 90s-2000s now. We're going through hypernormalisation of the west, this term came from late Soviet Union, where everything felt fake but everyone was playing along because they didn't feel like there was other options, and this is happening to us now.
Autism 'as we know it' is a diagnosis that seems unreal to a lot of writers, its definition has been constantly changing, for the last few decades we've believed it's an inborn brain condition and yet we couldn't find specific genes or area of the brain area that seems to be responsible. Every new theories seem to fail, from mirror neuron, to extreme male brain to intense world... because autism isn't one thing. Autism as a cultural idea has been going from severely disabled kids who don't speak to nerdy awkward men to corporate striver women who feel self-conscious sometimes. A lot of writers, unless they are progressive or 'fucking love science', don't really want to write 'diagnosed autistic' characters because the diagnosis robs context from the character, everything will be explained as 'their brain work differently'. It removes history, love and fear, and relabtability to most audience. But in fandoms obsessed with identity and representation, they want characters to be labelled autistic because to them, they believe in the label religiously and think it is truly objective, and anyone with associated traits should be representative of autism officially.