This is a wonderful tale of spelunking into standards from Darius Kazemi—I had no idea that HTTP status codes have their origin in a hastily made decision in the days of ARPANET.
20 people got together at MIT in 1972 for a weekend workshop. On the second day, a handful of people in a breakout session decided it would be a good idea to standardize error messages between two services for transferring data, even though those two services had not necessarily planned to speak to one another. One thing led to another, and now 404 is synonymous with “I can’t find the thing.”
This story is exactly the kind of layering of technologies that I was getting at in the first chapter of Resilient Web Design.
HTTP status codes are largely an accident of history. The people who came up with them didn’t plan on defining a numerical namespace that would last half a century or work its way into popular culture. You see this pattern over and over in the history of technology.