IN A DECEMBER 3, 1590, journal entry, Spanish explorer Gaspar Costaño de Sosa mentioned the small bonfires his cohorts had lit to guide a scout back to camp. Luminarias, he called them, thereby casting the first stone in what’s now a 426-year-old, northern-versus-southern New Mexico debate over the little paper bags that light up our holiday nights.

“They’re farolitos,” folks north of La Bajada Hill insist.

“Luminarias,” everyone south says.

Over the years, even linguists have disagreed. Their arguments for and against fill a fat file at the Fray Angélico Chávez History Library at the New Mexico History Museum in Santa Fe. Among the few certainties: Before the 1872 invention of flat-bottomed paper bags, before the ready availability of votive candles, and before electricity and strings of “icicle lights,” New Mexicans marked the paths to their doors and the local church with small, Sosa-style bonfires on Christmas Eve—symbolically lighting the way for the Holy Family.

Chinese paper lanterns found their way to Santa Fe via the 18th-century Manila galleons and El Camino Real, but the fragile paper didn’t invite outdoor use. Once cheaper paper bags arrived on the Santa Fe Trail, locals discovered they could fold down the tops, anchor them with a few handfuls of sand, and set a small candle inside for a subtler display that didn’t deplete the winter woodpile.

In Santa Fe, the Christmas Eve Farolito Walk on Canyon Road is a beloved community event. Photograph courtesy of Tourism Santa Fe.

But what to call them? Some folks stuck with luminaria—“light” in Spanish. Others adopted farolito, from farol, the Spanish word for “lantern.” In the 1930s, as more people got the paper-bag bug, newspaper articles dithered, alternately calling them farolitos, linternitas, and farolillos. In 1958, the august New York Times chimed in, but said Albuquerqueans called them farolitos, further confusing the geography. Before his 1996 death, author and historian Fray Angélico himself waded into the debate and essentially concluded, “Whatever.”

Today the bags-and-candles tradition stretches from California to Maine. In Santa Fe, the Christmas Eve Farolito Walk on Canyon Road is a beloved community event. Head out after sundown to stroll the streets (no cars allowed!) and meet some locals in front of their shops and homes. Just don’t compliment them on their luminarias. You’re in the north now. As for those plastic versions bedecking rooflines throughout the holiday season, take it from renowned Santa Fe archaeologist Cordelia Snow, whose 1991 letter to the Santa Fe New Mexican cheekily dubbed them “electrolitos.”

Read more: Call ’em what you want—farolitos or luminarias—here’s how to make paper bags bright.