You can't really tell without asking unless something random happens. For example, there was an art show at my high school recently and I saw what was obviously someone's fursona on display. My friends (non-furries) just said it was a strange drawing of a cat. I guess sometimes it does "take one to know one."
Yeah... Something like that getting out in school would basically spell the end of your social life. First, People would assume you're a hyperfag. Second, Teachers would get involved and tell your parents. Third, Your parents would get a priest to to give you an exorcism. Most likely outcome, You get burned on a cross.
I was a bit curious of how to tell because I noticed this one girl with this white fox tail on her purse. I approached and complemented it but maybe the message didn't get across.
I just ordered some paw print dogtags because of this thread.
Do what I do, don't look at FA in public, don't talk about it, and when talking to other furries, don't talk too loud. And NO Guerilla Fursuiting! Unless it fits the situation better...like a werewolf at a larp or something...Did everyone not read that he wants to keep the information that he himself is a furry out of the general public's hands.He wants to keep it "hush hush" so those of you who are proposing the noisy plans are not being helpful at all.