Maybe I'm strange, but I don't mind 'labels' as long as the diagnosis is accurate. (I think the 'don't label my child' thing has become a cliche concept that people parrot without really thinking it through.) I see the label as a comfort, because it helps me focus on what I need to do to fix it or at least treat it.
I was actually relieved when my first child was diagnosed, because it meant I wasn't a bad parent. Her delays did have an organic cause. [My parents had fussed at me for not reading to her enough (she wouldn't sit still for it) and my dad thought her delayed speech was because I let her watch Teletubbies.]
My parents are educated people, but parents always seem to look for blame with their kids, because they continue to see us as 'kids' and not responsible adults.
Anyhow... I've never hidden from my kids that they are dx with autism, but I also don't treat them like they are damaged or retarded or (pick your adjective). I love them and treat them like the smart, capable kids they are, and --while I try and plan for the possibilities of them having trouble or needing help later in life-- I try not to assume they can't do something or assume they won't achieve things in the future. I've done that easier with autistic child number two after watching the radical changes in number one and knowing I shouldn't judge their future abilities/functioning level by the present.
I truly feel how we treat them is far more important than the effect labels have. That is what determines how they view themselves, not some diagnosis printed in some file. And I don't know about things there, but here, they must have a label to get certain services. It is the diagnosing that qualifies them for the modifications and therapies they need. So I say, bring it on. Call them 'purple polkadotted' if you have too, just help them and get them what they need.
Regarding their dx, I don't say things in front of their friends (I leave that up to them), but I do mention it to other parents when appropriate. And I try to say things that give them a positive attitude in the process, too. "You know, we're real proud of [daughter]. It's hard to believe she didn't have any functional language at the age of three. She's come a long way since then." That comment is usually met with raised eyebrows, a look of pleasant surprise and an agreeing nod.
The symptoms I saw were: extreme stranger phobia from about 4 months in the first child, then words without true communication followed by increasingly odd and aloof behavior and poor eye contact by a year and a half. The second child was better about trying to communicate; he just didn't have the words. But after a while, as the first one came slowly back out of her shell, he progressively became more 'Rainman-ish'. Though there are similarities, they each manifest their autism (PDD NOS, to be specific) differently.
Hope this helps.