Section 32 of the United Kingdom's Salmon Act 1986 arrived with a heading so perfectly odd that it escaped the statute book and began living as trivia: “Handling salmon in suspicious circumstances.” Read quickly, it sounds as though lawmakers had identified a class of fish with poor alibis. The salmon is not the suspect.

In the section as enacted, the offense concerned a person who received salmon, helped retain, remove, or dispose of it, or arranged to do so while believing—or when it would have been reasonable to suspect—that a relevant offense had already been committed. The relevant wrongdoing involved the taking, killing, or landing of that salmon. The provision was aimed at the human chain around illegally obtained fish: the receiver, mover, or disposer who could not plausibly claim that everything looked normal.

That makes Section 32 closer to an anti-poaching and handling-stolen-goods rule than a ban on behaving furtively near seafood. “Suspicious circumstances” describes what the person knows or reasonably ought to suspect about the fish's history. It does not require a salmon to lurk under a streetlamp in a tiny trench coat.

The text also contained boundaries. A defendant could show that no relevant offense had in fact been committed. Conduct performed in good faith to prevent or detect crime, or to investigate or treat disease, was excluded. Beneath the immortal heading sits an ordinary legal task: defining when assistance after an offense becomes an offense of its own.

There is one useful update for collectors of strange laws. In 2010, amendments broadened the provision beyond salmon. The current revised text applies to several kinds of fish, including salmon, trout, eels, lampreys, smelt, and freshwater fish, and its official heading now reads “Handling fish in suspicious circumstances.” The famous salmon wording is genuine—it is the heading under which Section 32 was enacted—but it is historical wording, not the latest version.

The joke survived because the title compresses a serious problem into five words that sound like a detective story. The law watches the transaction. The circumstances carry the suspicion. The salmon may remain composed.