Why is Rag & Bone called Rag & Bone? Who are Alice and Olivia? And is Phillip Lim just really into rational numbers?

Some designers make it easy by naming their fashion lines directly after themselves (we're looking at you, Zac Posen and Rachel Comey). But other times, the nomenclature isn't quite as straightforward. The rad part about that? There's always a pretty interesting back story. So check out these 10 well-known designer brands to see why they're really called what they are.

3.1 Phillip Lim

So the "Phillip Lim" part of 3.1 Phillip Lim is pretty clear-cut, but what does the number mean? Well, there's a nice story about friendship and hard work behind that. According to Fast Company, the designer started his self-named line in 2005 with Wen Zhou, who is now CEO and president of the company—when both partners were aged 31 years old. Get it? 31, 3.1. Aw…

Alice + Olivia

The explanation behind this exuberantly girly line is near and dear to the founders' hearts. In 2002, former classmates at University of Pennsylvania Stacey Bendet and Rebecca Matchett started the brand (first with just pants!) and named it after their mothers, Alice and Olivia. Matchett left the company a year later, but the catchy brand name was already cemented into our sartorial consciousnesses. Now, the collection of apparel and accessories is officially called Alice + Olivia by Stacey Bendet.

Elizabeth and James

Already successful with The Row (and earlier on with their Wal-Mart kids' line), Mary-Kate and Ashley Olsen added the Elizabeth and James contemporary brand to their fashion portfolio in 2007. General perception is that the younger, hipper line was named for the twins' little siblings—the now famous Elizabeth and James Trent Olsen—but apparently, that's not the case. "We wanted to pick a male name and a female name," Ashley told USA Today that same year. "I remember saying Elizabeth and James, and being like, 'Oh, my gosh, that's our brother and sister!'" It was a coincidence—they just wanted a girl name and a boy name to emphasize the contrast between feminine style and a masculine edge. And MK & A actually call their sibs "Lizzie" and "Trent," so there.

The Gap

If it wasn't for original Gap co-founder Doris Fisher's moment of genius, your favorite store for denim and wardrobe basics could have been called Pants and Discs. True story. In 1969, entrepreneur and San Francisco native Don Fisher and his wife and partner opened up the first Gap store—selling Levi's and records—because Don couldn't find the perfect pair of jeans. The moniker was inspired by "The Generation Gap" (thank you, Doris), and the Fishers also stocked the store with LPs to appeal to the cool kids of the era. While they started selling Gap-branded products in 1974 and grew to become the Gap empire (including Banana Republic, Old Navy, and Piperlime), the Fishers were still very involved in the company. Don Fisher passed in 2009, but co-founder and widow Doris is still an inspiration for generations to come.

Helmut Lang

Now, Helmut Lang was the name of the Austrian designer who founded the minimalist, groundbreaking label (FYI, he was the first to show a collection on the internet in 1998). So that part is pretty easy. But Helmut walked away from his label in 2005 after things just weren't working out with Prada, which bought majority shares in the company in 1999. After then being sold to Theory, Helmut Lang (the brand) was relaunched in 2007 with husband and wife Michael and Nicole Colovos designing the label. More news: The couple just left Helmut Lang after designing this fall's collection, so it's up in the air as to who's in charge next. But at least we know where the original name came from…