Daniel Victor, The New York Times:

The relatively small-scale dispute gained international notoriety last year when the United States Court of Appeals for the First Circuit ruled that the missing comma created enough uncertainty to side with the drivers, granting those who love the Oxford comma a chance to run a victory lap across the internet.

But the resolution means there will be no ruling from the land’s highest courts on whether the Oxford comma — the often-skipped second comma in a series like “A, B, and C” — is an unnecessary nuisance or a sacred defender of clarity, as its fans and detractors endlessly debate. (In most cases, The Times stylebook discourages the serial comma, often called the Oxford comma because it was traditionally used by the Oxford University Press.)