GNU Terry Pratchett

A man is not dead while his name is still spoken.

• Going Postal, chapter 4

I added the x-clacks-overhead header to my site. In fact, it’s been there since my first post. Because of course, this felt essential to me.

Here’s why. With some slightly technical details about what and how.

What is a header? #

If you’ve not come across the term before, HTTP requests and responses (like when you ask a website to send you a page, and when it replies) contain ‘headers’. These do various important things. They will state what type of content is in the response (for example, text, or an image), so your browser knows what to do with it. Or they might tell your browser when the page was last modified, so it isn’t downloaded again if it hasn’t changed.

Headers can also be arbitrarily set by the server. If your browser doesn’t have any knowledge of them, they will simply be ignored.

GNU Terry Pratchett #

In the Discworld series, written by Sir Terry Pratchett, there’s a book called Going Postal. The story deals with topics around the Industrial Revolution.

A big part of the story is the development of a nationwide semaphore communication network. The system uses letter codes to indicate what to do with the message contents as they transit the network. The system is known as ’the clacks’.

One of the characters decides to use the clacks network to memorialise a loved one. The codes used in the story are GNU, followed by the name of his loved one. This simply means the name of his loved one bounces around the network indefinitely, never reaching a destination and always being passed along the line forever.

So, in a similar way, GNU Terry Pratchett might be used to memorialise Sir Terry.

The x-clacks-overhead header #

Some years ago, fans of Sir Terry thought of using an arbitrary HTTP header to memorialise him. And thus was born the x-clacks-overhead header.

It’s totally invisible to you. Your browser receives it, and does nothing with it. If you know where to look, you can find it. But every time you visit a site with this header set, Sir Terry is remembered. Nowadays, some sites use the header to remember other people they love, too, which seems entirely appropriate.

All of which means: every time somebody loads my blog, the name of Sir Terry is spoken. In my own small way, I am keeping him alive in the world.

Do any other sites do this? #

Yes! Quite a few. Mostly indie web stuff, like this blog.

But also some pretty big mainstream names, too. At least at the time of writing, I saw: Marks and Spencer; Ocado; The Register. Likely more that I didn’t spot.

There’s a big listing of all the known sites over on the X-Clacks-Overhead site.

How I did it #

I’m using Caddy as my web server. It makes it really easy to add arbitrary headers like this. Just had to add header x-clacks-overhead "GNU Terry Pratchett" to my Caddyfile, like this:

sitename {
        header x-clacks-overhead "GNU Terry Pratchett"
        root * /usr/share/caddy
        file_server
}

And that’s it. Good thing about Caddy is just how easy it makes many things.

Cover image #

Photo of Sir Terry Pratchett, licensed from Luigi Novi under CC-BY-3.0.