New HTTP error code 451 to signal censorship • The Register

After a three-year campaign, the IETF has cleared the way for a new HTTP status code to reflect online censorship.

The new code – 451 – is in honor of Ray Bradbury’s classic novel Fahrenheit 451 in which books are banned and any found are burned (451 degrees Fahrenheit being the auto-ignition temperature for paper).

The idea is that rather than a web server, proxy or some other system returning a 403 code to a browser when information is blocked – i.e. you are not authorized to see it – the 451 status code will mean “unavailable for legal reasons.” Specifically, according to a draft RFC:

Source: New HTTP error code 451 to signal censorship • The Register