I kid you not. It's apparently a kind of secret sign.
Last year, I took a class with the new Romanticist* in our department. He's what would I would call a preppy dresser: pressed dress shirt, cuff links, shined shoes. Always. In a department where some faculty rarely aspire beyond shorts and flip flops (and I am so okay with that), it sticks out, which is probably why I noticed his socks. Bright. Stripes. I actually looked forward to seeing what pair he'd be wearing every class. I took it as a kind of private rebellion against his own self-imposed dress code. (Romanticists are complicated people.)
And then, this last weekend at a nineteenth century conference, I overheard the following exchange:
Visiting Romanticist: I see you wear striped socks. You must be a Romanticist.
Our Romanticist: Oh yes!
Both: [lift pant cuffs to display brightly striped socks]
(*Romanticist - scholar who studies literature more or less written between 1750 and 1850.)