I voted "other", and feel invisible yet again.
First off, I don't believe in HFA vs. MFA vs. LFA or whatever, for reasons I've gotten into so many times I don't feel like getting into it again.
Second off, my diagnosis isn't AS, HFA, or PDD-NOS. It's autism. Just autism. Sometimes (and against my wishes, but it's been said) doctors have used terms like low-functioning or severe. (Please don't stereotype me based on this. Stereotypes based on any functioning label will turn out too wrong to explain briefly.)
As far as why I'm quiet (when I'm quiet)? Because language is really fricking hard. Because it takes an effort, like climbing a cliff with my fingernails, to climb into the realm of language at all, to even understand language when it's presented to me as anything other than noises and squiggles and such. (See here and here and here for details.)
Not the only reason but the biggest reason. And just as my diagnosis isn't listed, neither is my biggest reason for remaining quiet. (There are other reasons. Most of which don't match anything listed. I don't know the words for many of them right now.)
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"In my world it's a place of patterns and feel. In my world it's a haven for what is real. It's my world, nobody can steal it, but people like me, we live in the shadows." -Donna Williams