Cosas raras del protocolo HTTP

Muy interesante el sitio web HTTPWTF, en el que se explican cosas raras del protocolo HTTP.

Entre las cosas raras que aparecen, está Referer, que ya lo conocía y siempre me había llamado la atención:

The HTTP Referer header tells the server which page you came from previously, or which URL triggered a resource load. This has some privacy challenges, but it’s stuck around, and it’s sent in most requests made as you browse the internet.

Notably, it’s spelled wrong. This was added in the very early days of the web, and the unix spell checker at the time didn’t recognize either referer or referrer (the correct spelling). By the time anybody noticed, it was in serious use in infrastructure and tools all over the place, so nothing could be changed and we have to live with every browser request having a misspelled header forever.

Not especially important unless you’re writing code to read this header yourself, but a great parable for the challenges of network compatibility.

For maximum confusion and damage potential, new privacy/security headers related to this like Referrer-Policy do use the correct spelling.