Clacks Overhead
Discworld author Terry Pratchett died in 2015. His books were hugely popular, making him one of the most successfull authors of all time. To remember him, a group of redditers came up with the idea of implementing the clacks system from the book Going Postal in today's internet. This can done by adding the following bit of code to the head tag in any HTML file:
<meta http-equiv="X-Clacks-Overhead" content="GNU Terry Pratchett" />
It can also be implemented by configuring web servers to send an appropriate page header. In fact this is the better option, but I am not able to configure the web server, as I am using GitHub Pages to host the site.
I had implemented this years ago, whilst I still had my site running on Wordpress. After moving to a static site, I had forgotten about this and not added the clacks meta tag. Well, now it's back - just in time for the new year!
More information on the clacks headers is available here:
The site also lists a number of plugins which can notify you if you are visiting a site which has implemented the clacks header.