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A Uniform Resource Name (URN) Namespace for the Commission for the Management and Application of Geoscience Information (CGI)

The information below is for an old version of the document that is already published as an RFC.
Document Type
This is an older version of an Internet-Draft that was ultimately published as RFC 5138.
Author S.J.D. Cox
Last updated 2015-10-14 (Latest revision 2007-10-05)
RFC stream Internet Engineering Task Force (IETF)
Stream WG state (None)
Document shepherd (None)
IESG IESG state RFC 5138 (Informational)
Consensus boilerplate Unknown
Telechat date (None)
Responsible AD Lisa M. Dusseault
Send notices to
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
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   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 

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   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 (

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   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  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.

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      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. 

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   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).  

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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

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8.0 References

8.1 Normative References

   [RFC2141] Moats, R., "URN Syntax", RFC 2141, May 1997. Available 
             [online]: <>
   [RFC3406] Daigle, L. et al., "Uniform Resource Names (URN) Namespace 
             Definition Mechanisms", RFC 3406, October 2002.  Available 
             [online]: <>     
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]: <
   [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
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

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Intellectual Property

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

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