There's an old line that a neofan is a person in fandom who doesn't know what a neofan is, and since TAFF voter eligibility does require previous activity in fandom, I think knowing what TAFF is is a good shibboleth.

I don't agree - you could be an active costuming, or filking, or even convention fan without necessarily knowing what TAFF is. But if you had a friend running for TAFF, I think you would be a perfectly eligible active fan to vote in an election of fandom to send a fannish representative to another country.