“When is it appropriate to say hello to someone because they’re wearing a Penn sweatshirt?” I asked a friend this summer while we ate dinner at a sidewalk cafe in New York. “I mean, like, when you’re not at Penn.”

Before we could properly ponder the question ourselves, a man from the adjacent almost-too-close table — as sidewalk cafe tables often are — had cocked his head towards us. “I went to Penn, you know,” he shared.

Soon enough, the questions came. What do you study? (No, I’m not in Wharton.) Is my fraternity still cool? (Sure, why not?) Are you girls old enough to be having that glass of wine? (Almost.)

And then he and his wife were asking if they could have a few of our French fries.

Certainly, given the hundreds of thousands of people who have called this campus home, Penn can serve as common ground in a variety of social settings or businesses. But when is it appropriate to pick someone out of a crowd because they’re wearing the Red and the Blue? And when is it creepy?

In Philadelphia, New York, Boston or Los Angeles, where Penn alums abound, approaching someone on the street to comment on a Penn t-shirt might seem peculiar, at least in a highly public setting. However, in more far-flung locales, I have experienced an increased temptation to approach people wearing Penn attire. While studying abroad last year in Berlin, I crossed paths with a woman wearing a Penn hoodie on my very residential, quiet street. I didn’t say hello but I almost feel like I should have, because, you know, what are the odds?

Ultimately, though, I’ve found that situation overrides location. Stuck in an inexplicably long line at midnight in a foreign airport? Definitely inquire about the Penn attire. I did, and it turns out we had a common friend.

Thinking outside the Penn bubble, wearing any identifying item of clothing outside its home radius is, in many cases, a sure way to meet people — even those you hadn't planned on sharing a side plate with.