http://motherboard.vice.com/read/the-http-451-error-code-for-censorship-is-now-an-internet-standard

The HTTP 451 Error Code for Censorship Is Now an Internet Standard

Written by Michael Byrne, Editor
December 21, 2015

The 451 HTTP status code is now official in the eyes of the Internet Engineering Task Force (IETF), the independent organization responsible for many of the internet’s operating standards. Now, when an internet user hits a web page that has been blocked for legal reasons (read: censorship), they may be presented with a 451 error instead of the more generic 403 “forbidden” error. This is a win for transparency.

The 451 code has been on the table for two years now, having been first been put forth by software engineer Tim Bray in 2013, who was in turn inspired by a blog post by security thinker Terence Eden. Eden’s call for a censorship error code is clear enough:

My ISP have recently been ordered to censor The Pirate Bay. They have done so unwillingly and, it would seem, have complied only with the letter of the ruling. Their block is, for now, trivial to circumvent. I am concerned that this censorship will become more prevalent. As network neutrality dies, we will see more sites ordered to be blocked by governments who fear what they cannot understand.

So, Eden proposed a code and Bray ran with it, using “451” in reference to Ray Bradbury’s censorship dystopia Farhenheit 451. Web standards are, however, not changed overnight.

In a post published on Friday, Mark Nottingham, chair of the IETF HTTP Working Group, explains a bit more. ...

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