Is it a widely used thing?
DS is autistic, diagnosed aged 4 in 2016. Diagnosis is simply autism spectrum disorder, which I thought was normal.
I've spoke to and met a lot of other parents with children with autism and they refer to their child's autism as level 1/2/3. I know it differs per area but this was locally to me.
I met a parent who said her son had autism level 3 and asked what my sons level was. I was just baffled, I don't think he needs a level and I wouldn't know what it is anyway.
I have had always had the mindset that you are either autistic or you're not. Yes some children and adults are more severely effected than others but it is a spectrum and where a child can struggle in one area they can not struggle in another. There's no clear cut levels of autism imo.