The subtle details of clothing often hide interesting stories. Take a look at the back of your shirts, ever noticed that little loop? You’ll often find it on dress shirts for men, seemingly inconspicuous but with a couple of intriguing purposes you might not have known about.

While dress shirts are typically part of more formal attire, they can also be dressed down for a casual look when paired with the right pants and accessories. But that loop on the back? It wasn’t just arbitrarily placed there.

Originally, it was a thoughtful addition for those hitting the gym frequently. Its purpose? To make hanging the shirt on a hanger a breeze, especially when you’re on the go and need to transition from one place to another without fussing about where to put your shirt.

Interestingly, that little loop had a flirtatious function too. In the past, it was used as a subtle signal of relationship status. If the loop was out and visible, it supposedly indicated that the person was taken, hence not needing to hang around looking for a place to hang their shirt. However, over time, its significance has faded away, becoming just another mundane part of shirt design.

Fashion trends may have evolved dramatically over the last century, but some elements remain unchanged. Men’s clothing, in particular, holds onto certain timeless features. Case in point: the back-of-the-shirt loop.

Often termed a “locker loop” or even a whimsical “fairy loop”, it’s stitched onto most Oxford or button-down shirts. Its primary purpose? Hanging up the shirt. Legend has it that these loops trace back to U.S. sailors who used them to hang their shirts aboard ships.

During the 1960s, they became an integral part of mainstream menswear, especially on college campuses as part of the “preppy” look. Gant, a clothing manufacturer, is often credited with popularizing this button-down style across Ivy League campuses. The man behind the brand initially introduced this shirt design to Yale University’s shop for male students, and from there, its popularity spread far and wide.