Network Working GroupT. Bray
Updates: 2616 (if approved)June 11, 2012
Intended status: Standards Track 
Expires: December 13, 2012 

A New HTTP Status Code for Legally-restricted Resources


This document specifies an additional Hypertext Transfer Protocol (HTTP) status code for use when resource access is denied for legal reasons.

Status of this Memo

This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.

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This Internet-Draft will expire on December 13, 2012.

Copyright Notice

Copyright (c) 2012 IETF Trust and the persons identified as the document authors. All rights reserved.

This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents ( in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.

Table of Contents

1.  Introduction
2.  Requirements
3.  451 Unavailable For Legal Reasons
4.  Security Considerations
5.  IANA Considerations
6.  Normative References
Appendix A.  Acknowledgements
§  Author's Address


1.  Introduction

This document specifies an additional Hypertext Transfer Protocol (HTTP) status code for use when resource access is denied for legal reasons. This allows server operators to operate with greater transparency in circumstances where issues of law or public policy affect their operation. This transparency may be beneficial both to these operators and to end users.

Feedback should occur on the mailing list, although this draft is NOT a work item of the IETF HTTPbis Working Group.


2.  Requirements

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119] (Bradner, S., “Key words for use in RFCs to Indicate Requirement Levels,” March 1997.).


3.  451 Unavailable For Legal Reasons

This status code indicates that the server is subject to legal restrictions which prevent it servicing the request.

Since such restrictions typically apply to all operators in a legal jurisdiction, the server in question may or may not be an origin server. The restrictions typically most directly affect the operations of ISPs and search engines.

Responses using this status code SHOULD include an explanation, in the response body, of the details of the legal restriction; which legal authority is imposing it, and what class of resources it applies to. For example:

HTTP/1.1 451 Unavailable For Legal Reasons
Content-Type: text/html

<title>Unavailable For Legal Reasons</title>
<h1>Unavailable For Legal Reasons</h1>
<p>This request may not be serviced in the Roman Province of
Judea due to Lex3515, the Legem Ne Subversionem Act of AUC755,
which disallows access to resources hosted on servers deemed
to be operated by the Judean Liberation Front.</p>

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 restriction were removed, a request for the resource might still not succeed.


4.  Security Considerations


4.1.  451 Unavailable for Legal Reasons

The 451 status code is optional; clients cannot rely upon its use. It is imaginable that certain legal authorities may wish to avoid transparency, and not only forbid access to certain resources, but also disclosure that the restriction exists.


5.  IANA Considerations

The HTTP Status Codes Registry should be updated with the following entries:


6. Normative References

[RFC2119] Bradner, S., “Key words for use in RFCs to Indicate Requirement Levels,” BCP 14, RFC 2119, March 1997 (TXT, HTML, XML).


Appendix A.  Acknowledgements

Thanks to Terence Eden, whose blog observed that the existing status code 403 was not really suitable for this situation, and suggested the creation of a new status code

Thanks also to Ray Bradbury.

The author takes all responsibility for errors and omissions.


Author's Address

  Tim Bray