Three digits for every fate

Every HTTP response begins with three digits. The first names the class — 1xx informs, 2xx confirms, 3xx detours, 4xx blames the client, 5xx takes the blame — and the other two refine the verdict. The scheme comes from the HTTP/1.0 of the nineties, crossed HTTP/1.1 and reached RFC 9110 intact, which defines the semantics today; the IANA registry keeps the official list, number by number.

It so happens that the official list is larger than the web that uses it. Half a dozen codes carry all the traffic — 200, 301, 304, 404, 500 and neighbors — and the rest sits registered, correct, waiting: codes from protocols that never took off, reservations for futures that never came, an April Fools' joke with a number of its own.

Why a cabinet of curiosities

Before the modern museum separated art from science and the proper from the strange, there was the Wunderkammer — the cabinet of curiosities, where the naturalist kept in one room the fossil, the astrolabe and the unicorn horn (which was narwhal, but nobody checked). The criterion was not usefulness: it was wonder.

This collection adopts the criterion. 418 is the joke that became heritage; 306 is a frame without a painting, reserved for a code that never existed; 402 has waited three decades for a future that never came; 451 keeps a tribute to Bradbury inside the protocol. The useful, the dead and the absurd, on the same shelf — as tradition demands.

Why lots of little pages

For the same reason as the sister collections, the HTML Herbarium and the Shell Reliquary: every curiosity, every drawer, every ordering and this very text are separate HTML files, linked together, written by a generator a few hundred lines long. State becomes an address; the browser handles the rest.