Web Linking
RFC 5988

Internet Engineering Task Force (IETF)                     M. Nottingham
Request for Comments: 5988                                  October 2010
Updates: 4287
Category: Standards Track
ISSN: 2070-1721

                              Web Linking

Abstract

   This document specifies relation types for Web links, and defines a
   registry for them.  It also defines the use of such links in HTTP
   headers with the Link header field.

Status of This Memo

   This is an Internet Standards Track document.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Further information on
   Internet Standards is available in Section 2 of RFC 5741.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   http://www.rfc-editor.org/info/rfc5988.

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   Copyright (c) 2010 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

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   described in the Simplified BSD License.

Nottingham                   Standards Track                    [Page 1]
RFC 5988                       Web Linking                  October 2010

   This document may contain material from IETF Documents or IETF
   Contributions published or made publicly available before November
   10, 2008.  The person(s) controlling the copyright in some of this
   material may not have granted the IETF Trust the right to allow
   modifications of such material outside the IETF Standards Process.
   Without obtaining an adequate license from the person(s) controlling
   the copyright in such materials, this document may not be modified
   outside the IETF Standards Process, and derivative works of it may
   not be created outside the IETF Standards Process, except to format
   it for publication as an RFC or to translate it into languages other
   than English.

Table of Contents

   1. Introduction ....................................................3
   2. Notational Conventions ..........................................3
   3. Links ...........................................................4
   4. Link Relation Types .............................................5
      4.1. Registered Relation Types ..................................5
      4.2. Extension Relation Types ...................................6
   5. The Link Header Field ...........................................6
      5.1. Target IRI .................................................7
      5.2. Context IRI ................................................7
      5.3. Relation Type ..............................................8
      5.4. Target Attributes ..........................................8
      5.5. Examples ...................................................9
   6. IANA Considerations ............................................10
      6.1. Link HTTP Header Registration .............................10
      6.2. Link Relation Type Registry ...............................10
           6.2.1. Registering New Link Relation Types ................11
           6.2.2. Initial Registry Contents ..........................12
      6.3. Link Relation Application Data Registry ...................16
   7. Security Considerations ........................................17
   8. Internationalisation Considerations ............................18
   9. References .....................................................18
      9.1. Normative References ......................................18
      9.2. Informative References ....................................19
   Appendix A.  Notes on Using the Link Header with the HTML4
                Format ...............................................21
   Appendix B.  Notes on Using the Link Header with the Atom
                Format ...............................................22
   Appendix C.  Acknowledgements .....................................23

Nottingham                   Standards Track                    [Page 2]
RFC 5988                       Web Linking                  October 2010

1.  Introduction

   A means of indicating the relationships between resources on the Web,
   as well as indicating the type of those relationships, has been
   available for some time in HTML [W3C.REC-html401-19991224], and more