URN Namespace for NewsML Resources

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.

Copyright Notice

Copyright © The Internet Society (2001). All Rights Reserved.

Abstract

This document describes a URN (Uniform Resource Name) namespace for identifying NewsML NewsItems. A NewsItem is an information resource that is expressible as a NewsML element within a NewsML document conforming to the NewsML Document Type Declaration (DTD) as defined by the International Press Telecommunications Council (IPTC).

1. Introduction

NewsML is an XML format for packaging multimedia news resources. It has been created under the auspices of the International Press Telecommunications Council (IPTC), and version 1.0 was approved by the IPTC on 6 October 2000.

The same logical NewsItem may exist in multiple physical locations. The NewsML specification allows NewsItems to have multiple URLs, but only a single URN. It is the latter which then uniquely names the resource.

This namespace specification is for a formal namespace.

2. Specification Template

Namespace ID:

"newsml" requested.

Registration Information:

      Registration Version Number: 1
      Registration Date: 2000-11-07

Declared registrant of the namespace:

David Allen
[email protected]
IPTC
Royal Albert House
Sheet Street
Windsor
SL4 1BE

Declaration of structure:

The identifier has the following ABNF[6] specification:

      NSS = ProviderId ":" DateId ":" NewsItemId ":" RevisionId Update
      ProviderId = string
      DateId = date
      NewsItemId = string
      RevisionId = posint
      Update = 0*1( "A" / "U" )
      date = century year month day
      century = ( "0" posdig ) / ( posdig DIGIT )
      year = 1*2DIGIT
      month = ( 0 posdig ) / ( "1" ( "0" "1" "2" ) )
      day = ( 0 posdig ) / ( ( "1" / "2" ) DIGIT ) / "30" / "31"
      string = 1*char
      char = ALPHA / DIGIT / symbol / escape
      symbol = "(" / ")" / "+" / "," / "-" / "." / "=" / "@" / ";" /
        "$" / "_" / "!" / "*" / "'"
      escape = "%" HEXDIG HEXDIG
      posint = posdig *DIGIT
      posdig = "1" / "2" / "3" / "4" / "5" / "6" / "7" / "8" / "9"
      
      The ProviderId must be an Internet domain name, and must be owned
         by the organisation creating the NewsML resource and allocating
         the URN to it, at the date identified by the DateId.
      DateId is a date in ISO 8601 Basic Format (CCYYMMDD), and must
         correspond to a date at which the organisation allocating the
         URN owned the domain name specified in the ProviderId.
      The NewsItemId must be unique among all NewsItems emanating from
         the same provider and having the same DateId.
      RevisionId is a positive integer indicating which revision of a
         given NewsItem this is.  Any positive integer may be used, but
         it must always be the case that of two instances of a NewsItem
         that have the same ProviderId, DateId and NewsItemId, the one
         whose RevisionId has the larger value must be the more recent
         revision.  A RevisionId of 0 is not permitted.
      If the NewsItem contains an "Update" element or elements, then
         Update must be set to "U".  If the NewsItem consists only of a
         replacement set of NewsManagement data, then Update must be set
         to "A".  If neither of these is the case, then Update must be
         suppressed.

Relevant ancillary documentation:

      None

Identifier uniqueness considerations:

The combination of ProviderId and DateId serves to uniquely

identify the organisation that is allocating the URN. That organisation is responsible for ensuring the uniqueness of the DateId/NewsItemId/RevisionId combination.

Identifier persistence considerations:

A NewsML URN may only be allocated by an organisation that owns an

Internet domain name. The URN identifies a date on which the organisation owned that domain name. The combination of date and domain name will serve to uniquely identify that organisation for all time.

Process of identifier assignment:

The organisation identified by the ProviderId/DateId combination

is responsible for allocating a NewsItemId that is unique among all those that it allocates with that DateId.

Process of identifier resolution:

NewsML providers are responsible for the provision of a URN

resolution service, if any, for NewsML URNs they have assigned with a valid ProviderId/DateId combination.

Rules for Lexical Equivalence:

URNs are lexically equivalent if the ProviderId, DateId,

NewsItemId, and RevisionId are all identical (case-insensitive comparison).

Conformance with URN Syntax:

No special considerations beyond the syntax herein described.

Validation mechanism:

Organisations that allocate NewsML URNs are responsible for the

provision of a URN validation service, if any, for URNs they have assigned with a valid ProviderId/DateId combination.

Scope:

      Global

3. Examples

The following examples are representative of NewsML URNs, but may not refer to actual resources.

   urn:newsml:iptc.org:20001006:NewsMLv1.0:1
   urn:newsml:reuters.com:20000206:
              IIMFFH05643_2000-02-06_17-54-01_L06156584:1U

4. Security Considerations

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

References

   [1]  Rivers-Moore, D., "NewsML Version 1.0 Functional Specification",
   
        November 2000,
        <http://www.iptc.org/NewsML/specification/NewsMLv1.0.pdf>.
   
   [2]  Rivers-Moore, D., "NewsML Version 1.0 DTD", November 2000,
        <http://www.iptc.org/NewsML/DTD/NewsMLv1.0.dtd>.
   
   [3]  W3C, XML WG, "Extensible Markup Language (XML) 1.0", February
        1998, <http://www.w3.org/TR/REC-xml>.
   
   [4]  Moats, R., "URN Syntax", RFC 2141, May 1997.
   
   [5]  Daigle, L., van Gulik, D., Iannella, R. and P. Faltstrom, "URN
        Namespace Definition Mechanisms", RFC 2611, June 1999.
   
   [6]  Crocker, D. and P. Overell, "Augmented BNF for Syntax
        Specifications: ABNF", RFC 2234, November 1997.

Authors' Addresses

   Anthony B. Coates
   Reuters
   85 Fleet St
   London  EC4P 4AJ
   United Kingdom
   
   Phone: +44 20 75 42 21 65
   EMail: [email protected]
   
   David Allen
   IPTC
   Royal Albert House
   Sheet Street
   Windsor  SL4 1BE
   United Kingdom
   
   Phone: +44 17 53 70 50 51
   EMail: [email protected]
   
   Daniel Rivers-Moore
   Rivcom
   Lotmead Business Village
   Swindon  SN4 0UY
   United Kingdom
   
   Phone: +44 17 93 79 20 00
   EMail: [email protected]

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