Need help identifying a sign my autistic son is using.

I'm sure he does! I was asking more or less in regards to that sign you were asking about, if he was saying anything along with it. I know that there are such varied responses among the autism spectrum so I wasn't sure.

Yes, as I stated in a previous response he was saying "moon" and "window" which we would have included in the short video but the site wouldn't let us upload it, it kept telling us it was "too big". We shortened it and took out the verbal portions where he spoke those words as we figured they would be the least helpful when appealing to deaf people for assistance. Like most things with Scott, it is a mystery but we have moved past the then critical point ... thank goodness. He seems to have forgotten about the incident and hasn't mentioned it today so we won't bring it up again and risk reminding and thus upsetting him. He is the sweetest boy and it just rips our hearts out to see him hurt himself so a big thank you again to all who took time to help us in what was a critical period.

Glad he is much calmer today. The SIB (self injurious behaviors) I'm all too familiar with as the first building I worked in was the Behavior Treatment Unit. Lots of headbanging, hitting self, biting, aggression you name it...more challenging with the deaf (I don't remember if any of the clients campus wide had hearing aids...my core group didn't) and non-verbal.