As there is a “status code” for any possible issue or outcome with an HTTP connection attempt, so there should be one more code for revealing web censorship enforced by the local authorities. The idea comes from Tim Bray, co-creator of the XML markup language and now Developer Advocate at Google.
Bray proposed his “censorship error code” idea in a draft submitted to the Internet Engineering Task Force (IETF), an organization devoted to developing and promoting Internet standards in close cooperation with the W3C (World Wide Web Consortium) and other standard regulation groups.
The draft describes the new “Unavailable For Legal Reasons” status code 451 – a clear homage to the well-known dystopian novel by recently deceased writer Ray Bradbury – where the code “indicates that the server is subject to legal restrictions which prevent it servicing the request”.
The 451 error code “should” include an explanation with a clear indication of what law the censored site would infringe in the user’s own country, the draft says. Furthermore, the new HTTP status “implies neither the existence nor non-existence of the resource named in the request”, ie. the server or the web resource could be unavailable even outside of the fence.
Of course Tim Bray is aware of the fact that some censorship-loving government or country would like to hide not only the blocked resource, but the simple fact that something is censored as well: “the 451 status code is optional”, the draft says, “clients cannot rely upon its use” because “certain legal authorities may wish to avoid transparency” in every way they can.
Source: The H Open Source.