Geekdar

One of the things I noted at Worldcon was the number of people around the convention center who I could say immediately were going to be attendees. And it's taken a while to figure out what it was I was noticing.

I think it must have been a lack of following current fashion. If legible clothing, then not just the manufacturer or some similar lifestyle thing; or anoraks; or just long hair in men; or tweedy jackets.