Britain’s Supreme Court of Judicature has answered a question that has long puzzled late-night dorm-room snackers: What, exactly, is a Pringle? With citations ranging from Baroness Hale of Richmond to Oliver Wendell Holmes, Lord Justice Robin Jacob concluded that, legally, it is a potato chip.

The decision is bad news for Procter & Gamble U.K., which now owes $160 million in taxes. It is good news for Her Majesty’s Revenue and Customs  and for fans of no-nonsense legal opinions. It is also a reminder, as conservatives begin attacking Judge Sonia Sotomayor for not being a “strict constructionist,” of the pointlessness of labels like that.

In Britain, most foods are exempt from the value-added tax, but potato chips  known as crisps  and “similar products made from the potato, or from potato flour,” are taxable. Procter & Gamble, in what could be considered a plea for strict construction, argued that Pringles  which are about 40 percent potato flour, but also contain corn, rice and wheat  should not be considered potato chips or “similar products.” Rather, they are “savory snacks.”

The VAT and Duties Tribunal disagreed, ruling that Pringles  which have been marketed in the United States as “potato chips”  are taxable. “There are other ingredients,” the tribunal said, but a Pringle is “made from potato flour in the sense that one cannot say that it is not made from potato flour, and the proportion of potato flour is significant being over 40 percent.”