Believe it or not, it took a U.S. court to determine whether a Snuggie counts as a blanket or an article of clothing.

Why does a court care, you may ask? The simple answer: taxes. Blankets face an import duty of just 8.5 percent, compared to the much higher rate of 14.9 percent for garments.

That adds up—especially considering that Allstar Marketing Group sold more than 30 million Snuggies in its first five years. Earnings from the Snuggie matched the GDP of Samoa, Yahoo reported in 2013.

As this delightful U.S. Court of International Trade ruling notes, “The key inquiry… is whether the addition of sleeves transforms what may have been a blanket, into something that is not a blanket.”

The federal government wanted to classify Snuggies as clothing, categorizing along with a swimsuit or leotard. In support of this classification, the U.S. Department of Justice posited that Snuggies look like “clerical or ecclesiastical garments and vestments” or else perhaps “professional or scholastic gowns or robes.”

But the court agreed with Allstar, which argued that, in part because the Snuggie lacks any rear closure, it’s not an article “ordinarily worn.”

(Allstar did concede that “people have worn the Snuggie during pub crawls.”)

It came down to the very sleeves the DOJ said made the Snuggie a garment.

“The sleeves support, rather than detract from, the Snuggie’s ‘primary design and use’ as a blanket because they ostensibly enable the Snuggie to remain in place and keep the user warm while allowing the user to engage in certain activities requiring of their hands,” the court said, concluding that the Snuggie’s “essential characteristic” was to keep sedentary people warm.

— Jillian Kay Melchior writes for Heat Street and is a fellow for the Steamboat Institute and the Independent Women’s Forum.