The World Health Organization sets a list of medical conditions into well-used code called the "International Statistical Classification of Diseases and Related Health Problems," or ICD for short. The official alphanumeric ciphers are used in medical records and insurance claims worldwide, noting the wide range of ailments and conditions a human may experience—everything from "tuberculosis" and "gastric ulcers" to "struck by orca" and "burn due to water skis on fire."

The latter categories of unusual and puzzlingly specific conditions even inspired the 2014 book Struck by Orca: ICD-10 Illustrated.

But how often are these peculiar codes actually used? An insurance data company did the work to find out. The most bizarre ICD codes listed in the 2014 book, such as the title "struck by orca," were not used in the US in the last 12 months, which is both good and disappointing. But codes just slightly less bizarre were used—some quite a lot, such as W503: "accidental bite by another person."