Call 404 facts

While investigating facts about Call 404, I found out little known, but curios details like:

There is a 404 style error called '418 I'm a teapot', which is returned by tea pots requested to brew coffee.

Twitter had a HTTP status code (like 404 - Not Found) that was used when limiting users for too many requests. It's called 420 - Enhance your Calm

In my opinion, it is useful to put together a list of the most interesting details from trusted sources that I've come across. Here are 2 of the best facts about Call 404 I managed to collect.