IETF logoThe Internet Engineering Task Force (IETF) has as its mission “to make the internet work better by producing high quality, relevant technical documents that influence the way people design, use, and manage the Internet“.

As part of this work, the IETF develops and promotes voluntary Internet standards, in particular the standards that comprise the Internet protocol suite (TCP/IP).

These standards include HTTP status codes, which are derived from both IETF internet standards, IETF RFCs other specifications and some additional commonly used codes.

The IETF’s HTTP Working Group has recently published a draft RFC proposing a new HTTP status code – status code 451 – for use when resource access is denied as a consequence of legal demands.

The draft’s introduction gives the rationale for the proposal:

This document specifies a Hypertext Transfer Protocol (HTTP) status code for use when a server operator has received a legal demand to deny access to a resource or to a set of resources which includes the requested resource.

This status code can be used to provide transparency in circumstances where issues of law or public policy affect server operations. This transparency may be beneficial both to these operators and to end users.

Getting into detail, the draft states that responses using this status code should include an explanation in the response body of the details of the legal demand, i.e. the party making it, the applicable legislation or regulation and the classes of person and resource to which it applies.

The use of the 451 status code implies neither the existence nor non-existence of the resource named in the request. That is to say, it is possible that if the legal demands were removed, a request for the resource still might not succeed.

The draft also gives an example of status code 451 in action.

HTTP/1.1 451 Unavailable For Legal Reasons
Link: <https://spqr.example.org/legislatione>; rel=”blocked-by”
Content-Type: text/html

<html>
<head><title>Unavailable For Legal Reasons</title></head>
<body>
<h1>Unavailable For Legal Reasons</h1>
<p>This request may not be serviced in the Roman Province
of Judea due to the Lex Julia Majestatis, which disallows
access to resources hosted on servers deemed to be
operated by the People’s Front of Judea.</p>
</body>
</html>

For those unfamiliar with the People’s Front of Judea, here’s some background information. 🙂

One of the reasons behind the proposal is that existing status code 403 (Forbidden) was not really suitable for situations where legal demands mean access to resources is denied.

Comments on the draft will be received until 13th May 2016.

The numbering of the status code pays homage to science fiction author Ray Bradbury‘s 1953 dystopian novel, Fahrenheit 451.

Reposted from Bristol Wireless.