Movatterモバイル変換

Network Working Group                                             S. CoxRequest for Comments: 5138                                         CSIROCategory: Informational                                    February 2008A Uniform Resource Name (URN) Namespace for the Commissionfor the Management and Application of Geoscience Information (CGI)Status of This Memo   This memo provides information for the Internet community.  It does   not specify an Internet standard of any kind.  Distribution of this   memo is unlimited.Abstract   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   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 artifacts, 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 ofCox                          Informational                      [Page 1]

RFC 5138              A URN Namespace for the CGI          February 2008   a system of identifiers that is global in scope.  CGI is the lead   forum for statutory organizations that 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 at:   <http://www.iana.org/assignments/urn-namespaces>2.  URN Specification for the "cgi" NID   Namespace ID:      cgi   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      Keyworth      Nottingham      Nottinghamshire      NG12 5GG      U K      Attn. Ian Jackson (ij@bgs.ac.uk)   Declaration of syntactic structure:      The Namespace Specific String (NSS) of all URNs that use the "cgi"      NID has the following structure:      urn:cgi:{CGIResource}:{ResourceSpecificString}      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].Cox                          Informational                      [Page 2]

RFC 5138              A URN Namespace for the CGI          February 2008      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:      <http://www.cgi-iugs.org/CGIIdentifierScheme>      A URN resolver is available at:      <http://www.cgi-iugs.org/uri>      The resolver provides a registry of CGI URNs 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.      The registration tables and information are published and      maintained by CGINA on the CGI web site, indicated above.Cox                          Informational                      [Page 3]

RFC 5138              A URN Namespace for the CGI          February 2008   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:      <http://www.cgi-iugs.org/CGIIdentifierScheme>      and a set of registers is 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 a Resolution Discovery System      (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.   Scope:      Global3.  Examples   The following examples are representative URNs that have been   assigned by CGINA:   urn:cgi:document:CGI:CGIIdentifierScheme      - identifies the document that describes the CGI Identifier        Scheme.Cox                          Informational                      [Page 4]

RFC 5138              A URN Namespace for the CGI          February 2008   urn:cgi:register:CGI:CGIResourceClasses      - identifies the register of resource classes for which        identifiers from the CGI scheme may be provided.   urn:cgi:xmlns:CGI:GeoSciML:2.0      - is the XML namespace for version 2.0 of GeoSciML, which is owned        by CGI.   urn:cgi:schema:GGIC:MineralOccurences:1.0:XMI      - identifies the XML Metadata Interchange (XMI) representation of        version 1.0 of the Mineral Occurrences information model owned        by the (Australasian) Government Geoscience Information        Committee.   urn:cgi:featureType:CGI:GeoSciML:2.0:Fault      - identifies the Fault feature-type from version 2.0 of the        GeoSciML schema that is owned by CGI.   urn:ogc:serviceType:CGI:GSML-FS:1.0      - identifies version 1.0 of the "GSML-FS" service-type owned by        CGI.   urn:cgi:classifierScheme:ICS:StratChart:2004      - identifies the 2004 edition of the Stratigraphic Chart published        by the International Commission for Stratigraphy.   urn:cgi:classifier:ICS:StratChart:2004:Silurian      - identifies the geologic period designated Silurian from the 2004        edition of the Stratigraphic Chart published by the        International Commission for Stratigraphy.   urn:cgi:classifier:GSV:Lithology:UIUYG1245NN07      - identifies the concept given the designation UIUYG1245NN07 from        the lithology scheme published by Geoscience Victoria        (Australia).Cox                          Informational                      [Page 5]

RFC 5138              A URN Namespace for the CGI          February 2008   urn:cgi:feature:USGS:2feb49bc-6755-11dc-8314-0800200c9a66      - identifies a feature instance given the designation        2feb49bc-6755-11dc-8314-0800200c9a66 by the US Geological        Survey.   urn:cgi:object:SGU:552cb080-6755-11dc-8314-0800200c9a66      - identifies an object given the designation        552cb080-6755-11dc-8314-0800200c9a66 by the Geological Survey of        Sweden.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 the Open Geospatial Consortium (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 implement applications that access   CGI resources effectively, 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   experience.6.  Security Considerations   There are no additional security considerations other than those   normally associated with the use and resolution of URNs in general.Cox                          Informational                      [Page 6]

RFC 5138              A URN Namespace for the CGI          February 20087.  IANA Considerations   This document defines a URN NID registration of "cgi", which has been   entered into the IANA registry located at:   <http://www.iana.org/assignments/urn-namespaces>8.  References8.1 Normative References   [RFC2141] Moats, R., "URN Syntax",RFC 2141, May 1997.   [RFC3406] Daigle, L., van Gulik, D., Iannella, R., and P. Faltstrom,             "Uniform Resource Names (URN) Namespace Definition             Mechanisms",BCP 66,RFC 3406, October 2002.8.2 Informative References   [OGC-URN] Reed, C., "A URN namespace for the Open Geospatial             Consortium (OGC)", Work in Progress, October 2007.   [OGC-DEF] Whiteside, A., "Definition identifier URNs in OGC             namespace", OpenGIS Best Practice document, OGC 06-023r1,             August 2006.  Available [online]:             <http://portal.opengeospatial.org/files/?artifact_id=16339>9.  Acknowledgement   Thanks to Carl Reed for preparing the document, "A URN Namespace for   the Open Geospatial Consortium", upon which this submission is based.Author's Address   S.J.D. Cox   Commonwealth Scientific and Industrial Research Organisation   PO Box 1130   Bentley, WA, 6102, Australia   EMail: Simon.Cox@csiro.auCox                          Informational                      [Page 7]

RFC 5138              A URN Namespace for the CGI          February 2008Full Copyright Statement   Copyright (C) The IETF Trust (2008).   This document is subject to the rights, licenses and restrictions   contained inBCP 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 ORGANIZATION HE/SHE REPRESENTS   OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND   THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS   OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF   THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED   WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.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 inBCP 78 andBCP 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 athttp://www.ietf.org/ipr.   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   ietf-ipr@ietf.org.Cox                          Informational                      [Page 8]