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CoRE Target Attribute Registry
draft-bormann-core-target-attr-00

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This is an older version of an Internet-Draft whose latest revision state is "Replaced".
Author Carsten Bormann
Last updated 2022-10-23
Replaced by draft-ietf-core-target-attr, draft-ietf-core-target-attr
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draft-bormann-core-target-attr-00
CoRE Working group                                            C. Bormann
Internet-Draft                                    Universität Bremen TZI
Intended status: Informational                           23 October 2022
Expires: 26 April 2023

                     CoRE Target Attribute Registry
                   draft-bormann-core-target-attr-00

Abstract

   The Constrained RESTful Environments (CoRE) specifications apply Web
   technologies to constrained environments.  One important such
   technology is Web Linking [RFC8288], which CoRE uses as the basis for
   a number of discovery protocols, such as the Link Format [RFC6690] in
   CoAP's Resource Discovery Protocol (Section 7 of [RFC7252]) and the
   Resource Directory [RFC9176].

   Web Links can have Target Attributes, the names of which are not
   generally coordinated by the Web Linking specification (Section 2.2
   of [RFC8288]).  This short note introduces an IANA registry for
   coordinating names of Target Attributes when used in Constrained
   RESTful Environments.

About This Document

   This note is to be removed before publishing as an RFC.

   Status information for this document may be found at
   https://datatracker.ietf.org/doc/draft-bormann-core-target-attr/.

   Discussion of this document takes place on the core Working Group
   mailing list (mailto:core@ietf.org), which is archived at
   https://mailarchive.ietf.org/arch/browse/core/.  Subscribe at
   https://www.ietf.org/mailman/listinfo/core/.

Status of This Memo

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

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at https://datatracker.ietf.org/drafts/current/.

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   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on 26 April 2023.

Copyright Notice

   Copyright (c) 2022 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
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   Please review these documents carefully, as they describe your rights
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   provided without warranty as described in the Revised BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   3
   3.  Security considerations . . . . . . . . . . . . . . . . . . .   6
   4.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   6
     4.1.  Normative References  . . . . . . . . . . . . . . . . . .   6
     4.2.  Informative References  . . . . . . . . . . . . . . . . .   6
   Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . .   7
   Contributors  . . . . . . . . . . . . . . . . . . . . . . . . . .   7
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .   7

1.  Introduction

   (Please see abstract.)

   The original Web Linking specification Section 3 of [RFC5988] did not
   attempt to coordinate names of target attributes except for providing
   common target attributes for use in the Link HTTP header.  The
   current revision of that specification clarifies (Section 2.2 of
   [RFC8288]):

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   |  This specification does not attempt to coordinate the name of
   |  target attributes, their cardinality, or use.  Those creating and
   |  maintaining serialisations SHOULD coordinate their target
   |  attributes to avoid conflicts in semantics or syntax and MAY
   |  define their own registries of target attributes.

   This short note introduces an IANA registry for coordinating names of
   Target Attributes when used in Constrained RESTful Environments.

1.1.  Terminology

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in
   BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

2.  IANA Considerations

   This specification defines a new sub-registry for Target Attributes
   in the CoRE Parameters registry [IANA.core-parameters], with the
   policy "expert review" (Section 4.5 of [BCP26]).

   The expert is instructed to be frugal in the allocation of very short
   target attribute names, keeping them in reverse for applications that
   are likely to enjoy wide use and can make good use of their
   shortness.  The expert is also instructed to direct the registrant to
   provide a specification (Section 4.6 of [BCP26]), but can make
   exceptions, for instance when a specification is not available at the
   time of registration but is likely forthcoming.

   Each entry in the registry must include:

   Attribute Name:
      a lower case ASCII [STD90] string that starts with a letter and
      can contain digits and hyphen-minus characters afterwards
      ([a-z][-a-z0-9]*).  (Note that [RFC8288] requires target attribute
      names to be interpreted in a case-insensitive way; the restriction
      to lower case here ensures that they are registered in a
      predictable form).

   Brief description:
      a brief description

   Change Controller:
      (see Section 2.3 of [BCP26])

   Reference:

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      a reference document that provides a description of the target
      attribute, including the semantics for when the target attribute
      appears more than once in a link.

   Initial entries in this sub-registry are as listed in Table 1:

   +=========+===========+==========+==================================+
   |Attribute|Brief      |Change    |Reference                         |
   |Name     |description|Controller|                                  |
   +=========+===========+==========+==================================+
   |href     |reserved   |IESG      |[RFC6690]                         |
   |         |(not useful|          |                                  |
   |         |as target  |          |                                  |
   |         |attribute  |          |                                  |
   |         |name)      |          |                                  |
   +---------+-----------+----------+----------------------------------+
   |anchor   |reserved   |IESG      |[RFC6690]                         |
   |         |(not useful|          |                                  |
   |         |as target  |          |                                  |
   |         |attribute  |          |                                  |
   |         |name)      |          |                                  |
   +---------+-----------+----------+----------------------------------+
   |rel      |reserved   |IESG      |[RFC6690]                         |
   |         |(not useful|          |                                  |
   |         |as target  |          |                                  |
   |         |attribute  |          |                                  |
   |         |name)      |          |                                  |
   +---------+-----------+----------+----------------------------------+
   |rev      |reserved   |IESG      |[RFC6690]                         |
   |         |(not useful|          |                                  |
   |         |as target  |          |                                  |
   |         |attribute  |          |                                  |
   |         |name)      |          |                                  |
   +---------+-----------+----------+----------------------------------+
   |hreflang |(Web       |IESG      |[RFC8288]                         |
   |         |Linking)   |          |                                  |
   +---------+-----------+----------+----------------------------------+
   |media    |(Web       |IESG      |[RFC8288]                         |
   |         |Linking)   |          |                                  |
   +---------+-----------+----------+----------------------------------+
   |title    |(Web       |IESG      |[RFC8288]                         |
   |         |Linking)   |          |                                  |
   +---------+-----------+----------+----------------------------------+
   |type     |(Web       |IESG      |[RFC8288]                         |
   |         |Linking)   |          |                                  |
   +---------+-----------+----------+----------------------------------+
   |rt       |resource   |IESG      |Section 3.1 of [RFC6690]          |
   |         |type       |          |                                  |

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   +---------+-----------+----------+----------------------------------+
   |if       |interface  |IESG      |Section 3.2 of [RFC6690]          |
   |         |description|          |                                  |
   +---------+-----------+----------+----------------------------------+
   |sz       |maximum    |IESG      |Section 3.3 of [RFC6690]          |
   |         |size       |          |                                  |
   |         |estimate   |          |                                  |
   +---------+-----------+----------+----------------------------------+
   |ct       |Content-   |IESG      |Section 7.2.1 of [RFC7252]        |
   |         |Format hint|          |                                  |
   +---------+-----------+----------+----------------------------------+
   |obs      |observable |IESG      |Section 6 of [RFC7641]            |
   |         |resource   |          |                                  |
   +---------+-----------+----------+----------------------------------+
   |osc      |hint:      |IESG      |Section 9 of [RFC8613]            |
   |         |resource   |          |                                  |
   |         |only       |          |                                  |
   |         |accessible |          |                                  |
   |         |using      |          |                                  |
   |         |OSCORE     |          |                                  |
   +---------+-----------+----------+----------------------------------+
   |oscore-  |Group ID of|IESG      |Section 3 of                      |
   |gid      |the OSCORE |          |[I-D.tiloca-core-oscore-discovery]|
   |         |Group (join|          |                                  |
   |         |resource of|          |                                  |
   |         |the Group  |          |                                  |
   |         |Manager)   |          |                                  |
   +---------+-----------+----------+----------------------------------+
   |app-gp   |endpoint   |IESG      |Section 3 of                      |
   |         |name of the|          |[I-D.tiloca-core-oscore-discovery]|
   |         |application|          |                                  |
   |         |group      |          |                                  |
   |         |associated |          |                                  |
   |         |to the     |          |                                  |
   |         |OSCORE     |          |                                  |
   |         |Group (join|          |                                  |
   |         |resource of|          |                                  |
   |         |the Group  |          |                                  |
   |         |Manager)   |          |                                  |
   +---------+-----------+----------+----------------------------------+

         Table 1: Initial Entries in the Target Attributes Registry

   A number of names are reserved as they are used for parameters in
   links other than target attributes, a further set is predefined in
   [RFC8288].

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3.  Security considerations

   The security considerations of [RFC8288] apply, as do those of the
   discovery specifications [RFC6690], [RFC7252], and [RFC9176].

4.  References

4.1.  Normative References

   [BCP26]    Cotton, M., Leiba, B., and T. Narten, "Guidelines for
              Writing an IANA Considerations Section in RFCs", BCP 26,
              RFC 8126, DOI 10.17487/RFC8126, June 2017,
              <https://www.rfc-editor.org/info/rfc8126>.

   [IANA.core-parameters]
              IANA, "Constrained RESTful Environments (CoRE)
              Parameters", 8 June 2012,
              <https://www.iana.org/assignments/core-parameters>.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/info/rfc8174>.

   [RFC8288]  Nottingham, M., "Web Linking", RFC 8288,
              DOI 10.17487/RFC8288, October 2017,
              <https://www.rfc-editor.org/info/rfc8288>.

   [STD90]    Cerf, V., "ASCII format for network interchange", STD 80,
              RFC 20, DOI 10.17487/RFC0020, October 1969,
              <https://www.rfc-editor.org/info/rfc20>.

4.2.  Informative References

   [I-D.tiloca-core-oscore-discovery]
              Tiloca, M., Amsüss, C., and P. Van der Stok, "Discovery of
              OSCORE Groups with the CoRE Resource Directory", Work in
              Progress, Internet-Draft, draft-tiloca-core-oscore-
              discovery-12, 5 September 2022,
              <https://www.ietf.org/archive/id/draft-tiloca-core-oscore-
              discovery-12.txt>.

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   [RFC5988]  Nottingham, M., "Web Linking", RFC 5988,
              DOI 10.17487/RFC5988, October 2010,
              <https://www.rfc-editor.org/info/rfc5988>.

   [RFC6690]  Shelby, Z., "Constrained RESTful Environments (CoRE) Link
              Format", RFC 6690, DOI 10.17487/RFC6690, August 2012,
              <https://www.rfc-editor.org/info/rfc6690>.

   [RFC7252]  Shelby, Z., Hartke, K., and C. Bormann, "The Constrained
              Application Protocol (CoAP)", RFC 7252,
              DOI 10.17487/RFC7252, June 2014,
              <https://www.rfc-editor.org/info/rfc7252>.

   [RFC7641]  Hartke, K., "Observing Resources in the Constrained
              Application Protocol (CoAP)", RFC 7641,
              DOI 10.17487/RFC7641, September 2015,
              <https://www.rfc-editor.org/info/rfc7641>.

   [RFC8613]  Selander, G., Mattsson, J., Palombini, F., and L. Seitz,
              "Object Security for Constrained RESTful Environments
              (OSCORE)", RFC 8613, DOI 10.17487/RFC8613, July 2019,
              <https://www.rfc-editor.org/info/rfc8613>.

   [RFC9176]  Amsüss, C., Ed., Shelby, Z., Koster, M., Bormann, C., and
              P. van der Stok, "Constrained RESTful Environments (CoRE)
              Resource Directory", RFC 9176, DOI 10.17487/RFC9176, April
              2022, <https://www.rfc-editor.org/info/rfc9176>.

Acknowledgements

   TBD

Contributors

   Jaime Jiménez
   Ericsson
   Email: jaime@iki.fi

   Jaime provided the list of initial registrations.

Author's Address

   Carsten Bormann
   Universität Bremen TZI
   Postfach 330440
   D-28359 Bremen
   Germany

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   Phone: +49-421-218-63921
   Email: cabo@tzi.org

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