[Search] [pdf|bibtex] [Tracker] [WG] [Email] [Nits]

Versions: 00 rfc5138                                       Informational
Network Working Group                                         S.J.D. Cox
Internet-Draft                    Commonwealth Scientific and Industrial
draft-sjdcox-cgi-urn-00.txt                        Research Organisation
Intended status: Informational
Expires: April 4, 2008                                   October 4, 2007

            A URN namespace for the Commission for the Management
            and Application of Geoscience Information (CGI)

Status of this Memo

   By submitting this Internet-Draft, each author represents that any
   applicable patent or other IPR claims of which he or she is aware
   have been or will be disclosed, and any of which he or she becomes
   aware will be disclosed, in accordance with Section 6 of BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF), its areas, and its working groups.  Note that
   other groups may also distribute working documents as Internet-

   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."

   The list of current Internet-Drafts can be accessed at

   The list of Internet-Draft Shadow Directories can be accessed at

   This Internet-Draft will expire on April 4, 2008.

Copyright Notice

   Copyright (C) The IETF Trust (2007).


   This document describes a URN (Uniform Resource Name) namespace that
   is engineered by the Commission for the Management and Application of
   Geoscience Information (CGI) for naming (i) persistent resources
   published by the CGI, and (ii) resources published by organizations
   that wish them to be used in the context of services conforming to
   protocols and agreements issued by CGI.  The formal Namespace
   identifier (NID) is "cgi".

1. Introduction

   CGI is a Commission of the International Union of Geological Sciences
   (IUGS) concerned with developing best practices in the management and
   application of geoscience information.  The active membership is
   primarily drawn from organizations with statutory responsibility for
   providing geoscience information to external users (e.g. Geologic

Cox                    draft-sjdcox-cgi-urn-00.txt             [Page 1]

Internet-Draft         A URN namespace for the CGI         October 2007

   Surveys).  An important focus of activity is the development of
   standards for networked data interchange, to complement or supersede
   the traditional map product.

   A number of documents, definitions, and other artefacts, are required
   to support this.  CGI wishes to provide persistent, location-
   independent Identifiers for these resources.  In addition,
   organizations that subscribe to the interchange standards proposed by
   CGI require external identifiers for data objects that are
   transferred.  CGI wishes to provide a scheme to enable data providers
   to uniquely identify data, which is consistent with the requirements
   of the interchange framework.

   Products and services that conform to CGI endorsed interchange
   specifications enable users to exchange and process geoscience
   information across networks, computing platforms, and products.
   Interoperability in such an environment is facilitated by the use of
   a system of identifiers that is global in scope.  CGI is the lead
   forum for statutory organizations which act as primary providers of
   technical data in this application domain.

   Motivated by these concerns, CGI would like to assign formal URNs to
   published resources in order to provide persistent, location-
   independent identifiers for them.  The process for registering a
   namespace identifier is documented in [RFC3406].

   The official IANA registry of URN namespaces is available online:

2. URN Specification for "cgi" NID

   Namespace ID:

      The NID "cgi" is requested.

   Registration Information:

      Registration Version Number: 1
      Registration Date: 2007-10-04

   Declared registrant of the namespace:

      Commission for Geoscience Information (Secretariat)
      c/o British Geological Survey
      Kingsley Dunham Centre
      NG12 5GG
      U K
      Attn. Ian Jackson (ij@bgs.ac.uk)

Cox                    draft-sjdcox-cgi-urn-00.txt             [Page 2]

Internet-Draft         A URN namespace for the CGI         October 2007

   Declaration of syntactic structure:

      The Namespace Specific String (NSS) of all URNs that use the "cgi"
      NID has the following structure:


      where the "CGIresource" is a US-ASCII string that conforms to the
      URN syntax requirements [RFC2141] and defines a specific class of
      resource type.  Each resource type has a specific labeling scheme
      that is covered by "ResourceSpecificString", which also conforms
      to the naming requirements of [RFC2141].

      The CGI maintains a naming authority, the CGI Naming Authority
      (CGINA), that manages the assignment of "CGIresource" classes, and
      the specific registration values assigned for each resource class.

   Relevant ancillary documentation:

      The CGI Naming Authority (CGINA) provides information on the
      registered resources and the registrations for each.  More
      information about CGINA and the registration activities and
      procedures to be followed are available at:


      A URN resolver is available at http://www.cgi-iugs.org/uri.  The
      resolver provides a registry of CGI URN's used in CGI services.

   Identifier uniqueness considerations:

      The CGINA manages resources using the "cgi" NID and is the
      authority for managing the resources and subsequent strings
      associated.  In the associated procedures, CGINA ensures the
      uniqueness of the strings themselves or permits secondary
      responsibility for management of well-defined sub-trees.

      CGI may permit use of experimental type values that will not be
      registered.  As a consequence, multiple users may end up using the
      same value for separate uses.  As experimental usage is only
      intended for testing purposes, this should not interfere with
      operational services.

   Identifier persistence considerations:

      CGINA provides clear documentation of the registered uses of the
      "cgi" NID.  This is structured such that each CGIResource has a
      separate description and associated ResourceSpecificString with
      separate registration tables for elements of the strings that are
      separately maintained.

Cox                    draft-sjdcox-cgi-urn-00.txt             [Page 3]

Internet-Draft         A URN namespace for the CGI         October 2007

      The registration tables and information are published and
      maintained by CGINA on the CGI web site, indicated above.

   Process of identifier assignment:

      CGINA defines CGIResource classes used with the "cgi" NID, and
      specifies the process for identifier assignment for each class.
      These are described at
      and a set of registers linked from there. Each such resource may
      have three types of registration activities:

         1) Registered values associated with CGI resources
         2) Registration of values or sub-trees to other entities
         3) Name models for use in experimental purposes

   Process for identifier resolution:

      The namespace is not listed with an RDS; this is not relevant.

   Rules for Lexical Equivalence:

      No special considerations; the rules for lexical equivalence of
      [RFC2141] apply.

   Conformance with URN Syntax:

      No special considerations.

   Validation mechanism:

      None specified.  URN assignment will be handled by procedures
      implemented in support of CGINA activities.



3. Examples

   The following examples are representative urns that have been
   assigned by CGINA.


   identifies the document that describes the CGI Identifier Scheme.


   identifies the register of resource classes for which identifiers
   from the CGI scheme may be provided.

Cox                    draft-sjdcox-cgi-urn-00.txt             [Page 4]

Internet-Draft         A URN namespace for the CGI         October 2007


   is the XML namespace for version 2.0 of GeoSciML which is owned by


   identifies the XMI representation of version 1.0 of the Mineral
   Occurrences information model owned by the Australasian Government
   Geologists Information Committee.


   identifies the Fault feature-type from version 2.0 of the GeoSciML
   schema that is owned by CGI.


   identifies version 1.0 of the "GSML-FS" service-type owned by CGI.


   identifies the geologic period designated Silurian by the
   International Commission for Stratigraphy.


   identifies the concept given the designation MelbourneFormation
   by Geoscience Victoria (Australia).


   identifies the 2004 edition of the Stratigraphic Chart published
   by the International Commission for Stratigraphy.


   identifies a feature instance given the designation
   2feb49bc-6755-11dc-8314-0800200c9a66 by US Geological Survey.


   identifies an object given the designation
   552cb080-6755-11dc-8314-0800200c9a66 by Sveriges geologiska
   undersokning (Sweden).

Cox                    draft-sjdcox-cgi-urn-00.txt             [Page 5]

Internet-Draft         A URN namespace for the CGI         October 2007

4. Namespace Considerations:

   There is currently no available namespace that will allow the CGI to
   uniquely specify and access resources, such as schemas and
   registries, that are required by organizations implementing CGI
   standards.  There is also a need for other standards organizations,
   such as OGC to be able to access CGI specific resources.

   The CGI members considered use of other existing NIDs, such as those
   for OGC.  However, these do not support the semantics required and in
   particular do not allow for the delegation of identifier assignment
   within the CGI community that is demonstrated here.

5. Community Considerations

   CGI standards require access to resources, such as schemas,
   registries, catalogues, documents, and services.  In order for the
   larger IT community to be able to effectively implement applications
   that access CGI resources, a unique namespace is required.  We desire
   these resources to be freely and openly available as a set of
   community resources.

   The design of the CGI namespace builds on the experience of the Open
   Geospatial Consortium (OGC) which has defined the framework of
   geospatial services within which CGI standards have been developed.
   The OGC membership has expertise in using the OGC URN [OGC-URN]
   [OGC-DEF], gained through implementation experiments and a variety of
   operational testbeds.  The CGI namespace is compatible with this

6. Security Considerations

   There are no additional security considerations other than those
   normally associated with the use and resolution of URNs in general.

7. IANA Considerations

   This document defines a URN NID registration of "cgi", which shall
   be entered into the IANA registry located at

Cox                    draft-sjdcox-cgi-urn-00.txt             [Page 6]

Internet-Draft         A URN namespace for the CGI         October 2007

8.0 References

8.1 Normative References

   [RFC2141] Moats, R., "URN Syntax", RFC 2141, May 1997. Available
             [online]: <http://www.ietf.org/rfc/rfc2141.txt>

   [RFC3406] Daigle, L. et al., "Uniform Resource Names (URN) Namespace
             Definition Mechanisms", RFC 3406, October 2002.  Available
             [online]: <http://www.ietf.org/rfc/rfc3406.txt>

8.2 Informative References

   [OGC-URN] Reed, C., "A URN namespace for the Open Geospatial
             Consortium (OGC)", Internet Draft draft-creed-ogc-urn-02,
             August 2007. Available [online]: <http://www.ietf.org/

   [OGC-DEF] Whiteside, A., "Definition identifier URNs in OGC
             namespace", OpenGIS Best Practice document, OGC 06-023r1,
             August 2006.  Available [online]:

   Author's Address

   S.J.D. Cox
   PO Box 1130
   Bentley, WA, 6102, Australia
   Email:   Simon.Cox@csiro.au

Full Copyright Statement

   Copyright (C) The IETF Trust (2007).

   This document is subject to the rights, licenses and restrictions
   contained in BCP 78, and except as set forth therein, the authors
   retain all their rights.

   This document and the information contained herein
   are provided on an "AS IS" basis and THE CONTRIBUTOR, THE

Cox                    draft-sjdcox-cgi-urn-00.txt             [Page 7]

Internet-Draft         A URN namespace for the CGI         October 2007

Intellectual Property

   The IETF takes no position regarding the validity or scope of any
   Intellectual Property Rights or other rights that might be claimed to
   pertain to the implementation or use of the technology described in
   this document or the extent to which any license under such rights
   might or might not be available; nor does it represent that it has
   made any independent effort to identify any such rights.  Information
   on the procedures with respect to rights in RFC documents can be
   found in BCP 78 and BCP 79.

   Copies of IPR disclosures made to the IETF Secretariat and any
   assurances of licenses to be made available, or the result of an
   attempt made to obtain a general license or permission for the use of
   such proprietary rights by implementers or users of this
   specification can be obtained from the IETF on-line IPR repository at

   The IETF invites any interested party to bring to its attention any
   copyrights, patents or patent applications, or other proprietary
   rights that may cover technology that may be required to implement
   this standard.  Please address the information to the IETF at

   Thanks to Carl Reed for preparing the I-D "A URN Namespace for the
   Open Geospatial Consortium", upon which this submission is based.

Cox                    draft-sjdcox-cgi-urn-00.txt             [Page 8]