HTTP 451 Error Code Indicating Censored Content A Hat Tip To Ray Bradbury


The Internet Engineering Steering Group (IESG), which is responsible for the Internet standards process, has pretty much approved HTTP 451 as the standard error code to indicate a webpage or website has been removed due to legal reasons — or in other words, censorship. Currently in Internet-Draft status,  Mark Nottingham (current chair of the IEFT HTTP Working Group) has indicated that the document will soon be an RFC after editing by the RFC editor. The full description of the code when it is finalized will be “HTTP/1.1 451 Unavailable For Legal Reasons,” and Nottingham indicates that websites can start using HTTP 451 now.

Initially suggested by Tim Bray back in 2012, the code is meant to augment the HTTP 403 status code “Forbidden” by providing further detail for pages that can’t be accessed for legal reasons. The new status code initially received pushback from Nottingham and others, as HTTP status codes are a constrained namespace, but as sites started to adopt it experimentally and it garnered more support, including from EITF Chair Jari Arkko, HTTP 451 gained the required support to become an Internet standard.

Nottingham explains what HTTP 451 can and can’t do:

By its nature, you can’t guarantee that all attempts to censor content will be conveniently labeled by the censor. Although 451 can be used both by network-based intermediaries (e.g., in a firewall) as well as on the origin Web server, I suspect it’s going to be used far more in the latter case, as Web sites like Github, Twitter, Facebook and Google are forced to censor content against their will in certain jurisdictions.

Many on the Internet will undoubtedly recognize the nod to Ray Bradbury and his dystopian novel Fahrenheit 451, in which books are banned and any that are found are subsequently burnt by “firemen.”

What do you think about the addition of an HTTP 451 status code? Let us know in the comments below, or on Google+, Twitter, or Facebook.

  Source: Matt Nottingham  Source: IETF

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