Hi annikins "Runesigil - totally agree that that info would be very helpful for host. Just thinking about how often I may have to explain that is making me think about getting little cards printed! Your explanation is very concise and accurate - mind if I borrow it?!"
My pleasure, use anything you need. You could have a few different versions depending on the occasion, some could include I don't get jokes very often, I'm very blunt, I'm clumsy at socialising, Please give simple instructions etc.
It may well be worthwhile adding things that are not easily picked up, the food issue for example has to be understood by the host as not just another fussy spoiled child that will come to no harm if they ignore your instructions.
The most important thing for other people to notice and understand in my experience is the transition into meltdown. It appears to them to be bad behaviour and every instinct if you've only known NT kids is at that point to be stern and tell them to behave, but for kids on the spectrum it's a sign of overwhelm, so instead of a reprimand at that point, the ASD child needs calming down, a quiet space and understanding until they've had chance to process everything that's going on.
Popular TV helps with a short explanation people can remember, despite the sweeping generalisation,
I always think Sheldon Cooper behaviour = ordinary
Kevin the Teenager behaviour = a cry for help because of overwhelm.
A lot of the replies on here are from people who do have experience, I'm not sure the outside world will have such a high ratio, but all you can do, like the rest of us is try to have your child's needs met with a little understanding. Autistic spectrum disorders, learning difficulties and disabilities are very much more publicised in the last few years.
The Special Needs Chat forum is a mine of information and support www.mumsnet.com/Talk/special_needs_chat