URI, URL and URN

1
URI, URL and URN

• URI (Uniform Resource Identifier) is a compact
  sequence of characters that identifies an
  abstract or physical resource.
• URL (Uniform Resource Locator) is a URI that is
  the location of a resource available via the
  Internet.
• http//www.animals.com/registry/Babar
• This is a resource which can be downloaded
  (perhaps an HTML document)
• URN (Uniform Resource Name) is a URI that is
  location-independent (i.e. does not specify a
  location.
• urn123456Babar
• This is a resource which cannot be downloaded.
  Elephants real or imaginary cannot be stored in a
  computer. Documents about them can.
• A resolution service may be provided which
  specifies URLs relevant to a URN.
• A URN namespace identifier (the second field) is
  either a number or human interpretable text
  string.
• IETF allocates numbers freely on a first come
  first served basis.
• IETF allocates text strings only to responsible
  organisations who have documented the namespace

2
Use of ISO/IEC 11179 in SC4

• ISO/IEC 11179-62005 Information technology
  Metadata Registries (MDR) Part 6 Registration
• Defines an International Registration Data
  Identifier (IRDI) for an administered item
• Usage specified by
• ISO/WD 290002-20 Concept dictionary resolution
  services
• ISO/WD 15926-6 Methodology for the development
  and validation of reference data
• Questions
• Does 11179-6 work for identifying EXPRESS
  entities and module reference data?
• IDW (David Price) will investigate.
• Does 11179-6 work for the ISO "concept database"?
• A problem for ISO CS.

3
IRDI as a URN

• Users of ISO/IEC 11179-6 want an URN that is
  equivalent to an IRDI.
• This can be
• urnmetadataltIRDI as a single stringgt
• The namespace identifier "metadata" is just a
  suggestion.
• ISO/WD 29002-1 specifies how a IRDI is
  represented as a single string
• The URN namespace has to be agreed between a
  responsible organisation (e.g. ISO, IEC) and
  IETF.
• SC4 needs to request somebody (e.g. ISO or IEC)
  to initiate this.
• The URN namespace "iso" is not appropriate
  because a registration agency using ISO/IEC
  11179-6 is not necessarily a standardisation body.

4
Example of an IRDI OTD identifier
ISO/IEC 11179-6
Registration Authority Identifier (RAI)
Annex A defines the international
registrationdata identifier (IRDI)
Separator Character
VersionIdentifier
Data Identifier


0161
1
-
Concept Code
Separator Character
Code Space Identifier (CSI)
Organization Identifier
Separator Character
ISO 22745-13
International Code Designator (ICD) value
ISO/IEC 6523
defines syntax and requirementsfor concept
identifiers
defines requirements for identification of
organization identification schemes
5
Can the iso URN namespace be used for ISO
metadata?

• This is not the intent of the namespace.
• techdefined" represents an associated or
  embedded resource defined by the committee that
  develops or maintains the identified document.
  All such "additions" begin with the keyword
  "tech", but the further syntax is defined by the
  committee.
• This is intended to identify associated or
  embedded documents, such as issues logs or
  EXPRESS files, not metadata.
• Metadata defined in modules, uses this URN
  namespace at present
• Do we persist in this "misuse"?
• Do we instead misuse URLs (as OASIS does)?
• e.g. http//www.tc184-sc4.org/metadata/xxxxx
• Do we delay publication of the modules until we
  have a metadata URN?
• Do we use an experimental URN or numeric URN
  temporarily?
• Do we go under an existing namespace (e.g.,
  OASIS)?

6
iso URN for SC4 documents

• A URN namespace has been agreed between ISO and
  IETF for the identification of ISO documents.
• Will the URN be added to the cover of standards
  documents by ISO CS?
• Do we amend the SC4 Supplementary Directives to
  specify an annex which states the URN?
• The URN is derived from the ISO document
  identification structure, but stating it
  explicitly may be useful.