Non specialists?
What like my son's comm paed who said 'but the GP said he's a smiley boy'
Smiling, having a sense of humour, eye contact, pointing, waving are all used 'red flags' or pointers rightly or wrongly...
Red flags / pointers are ONLY helpful when seen a big picture..,
CHAT, ASQ, SOGS, PEDS, etc etc are all only helpful IF you take a full history and listen to a parent. I lack of pointing in a child that has suffered neglect for example is not necessarily a sign of pointing...
Or a child with a sibling with autism might need parents to be given advice to use groups, have some portage to improve their skills / experiences in play & speech.
But then I have a child who's lack of 'red flags' meant he wasn't diagnosed until he was 6 and missed every opportunity for early intervention... In fact even WITH a diagnosis I am STILL battling because of his lack of red flags...
Nothing to do with being told all his life, by settings that it's naughty to spin, stroke, lick, tap, hum, flap... Nothing to do with being bullied for having support because he looks normal. Nothing to do with teachers ignoring his statement because he laughs when it's appropriate to laugh...
Your red flags can take a running leap because they are destroying my child's self esteem and his need to be understand.
There is no quick tick list for anything - we all individual.