X.500 labeledURL Attribute Type                              Mark Smith
INTERNET-DRAFT                                   University of Michigan
                                                        8 November 1994

       Definition of an X.500 Attribute Type and Object Class to
                 Hold Uniform Resource Locators (URLs)
               Filename: draft-ietf-asid-x500-url-00.txt

Status of this Memo

   This document is an Internet-Draft.  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-Drafts.

   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.''

   To learn the current status of any Internet-Draft, please check
   the ``1id-abstracts.txt'' listing contained in the Internet-
   Drafts Shadow Directories on ds.internic.net (US East Coast),
   nic.nordu.net (Europe), ftp.isi.edu (US West Coast), or
   munnari.oz.au (Pacific Rim).

   Distribution of this memo is unlimited.  Editorial comments should be
   sent to the author (mcs@umich.edu).  Technical discussion will take
   place on the IETF ASID mailing list (ietf-asid@umich.edu).

   This Internet Draft expires May 12th, 1995.

Abstract

   Uniform Resource Locators (URLs) as defined by [1] are being widely
   used to specify the location of Internet resources.  There is an
   urgent need to be able to include URLs in the X.500 [2,3] Directory.
   A number of independent groups are already experimenting with the
   inclusion of URLs in the X.500 Directory through the use of existing
   or newly defined attribute types.  This document builds on the
   experimentation to date and defines a new attribute type and an
   auxiliary object class to allow URLs to be included in X.500
   Directory entries in a standard way.  It is intended that the schema
   elements defined in this document will be progressed according to the
   process defined by the Internet X.500 Schema Working Group [4].





Smith                                                           [Page 1]


INTERNET-DRAFT      X.500 labeledURL Attribute Type      8 November 1994


Schema Definition of labeledURL Attribute Type

   Name:             labeledURL
   ShortName:
   Description:      Uniform Resource Locator with optional label
   OID:              umichAttributeType.41 (1.3.6.1.4.1.250.1.41)
   Syntax:           caseExactString
   SizeRestriction:  None
   SingleValued:     False

Discussion of the labeledURL Attribute Type

   The labeledURL attribute type has the caseExactString syntax (since
   URLs are case-sensitive) and it is multivalued.  Values placed in the
   attribute should consist of a URL, optionally followed by one or more
   space characters and a label.  Since space characters are not allowed
   to appear un-encoded in URLs, there is no ambiguity about where the
   label begins.  The URL portion must comply with the URL specification
   [1].  Multiple labeledURL values will generally indicate different
   resources that are all related to the X.500 object, but may indicate
   different locations for the same resource.

   The label is used to describe the resource to which the URL points,
   and is intended as a friendly name fit for human consumption.  This
   document does not propose any specific syntax for the label part.
   Note that in some cases it may be helpful to include in the label
   some indication of the kind and/or size of the resource referenced by
   the URL.

   Note that the label may include any characters allowed by the
   caseExactString syntax, but that the use of non-IA5 (non-ASCII)
   characters is discouraged as not all directory clients may handle
   them in the same manner.

   Some examples of valid labeledURL values (the first does not have a
   label):

     ftp://ds.internic.net/rfc/rfc1588.txt

     http://www.umich.edu/ University of Michigan Home Page

     http://champagne.inria.fr/Unites/rennes.gif Rennes [photo]









Smith                                                           [Page 2]


INTERNET-DRAFT      X.500 labeledURL Attribute Type      8 November 1994


Schema Definition of labeledURLObject Object Class

   Name:              labeledURLObject
   Description:       object that contains the labeledURL attribute type
   OID:               umichObjectClass.14 (1.3.6.1.4.1.250.3.14)
   SubclassOf:        top
   MustContain:
   MayContain:        labeledURL

Discussion of the labeledURLObject Object Class

   The labeledURLObject class is a subclass of top and may contain the
   labeledURL attribute.  The intent is that this object class can be
   added to existing objects to allow for inclusion of labeledURL
   values.  This approach does not preclude including the labeledURL
   attribute type directly in other object classes as appropriate.

References

   [1] Berners-Lee, T., Masinter, L., and McCahill, M., "Uniform
   Resource Locators (URL)", Internet Draft (Work In Progress) of the
   IETF URI Working Group, <URL:ftp://ds.internic.net/internet-
   drafts/draft-ietf-uri-url-08.txt>

   [2] The Directory: Overview of Concepts, Models and Service.  CCITT
   Recommendation X.500, 1988.

   [3] Information Processing Systems -- Open Systems Interconnection --
   The Directory: Overview of Concepts, Models and Service.  ISO/IEC JTC
   1/SC21; International Standard 9594-1, 1988.

   [4] Howes, T., Rossen, K., Sataluri, S., and Wright, R., "Procedures
   for Formalizing, Evolving, and Maintaining the Internet X.500
   Directory Schema", Internet Draft (Work In Progress) of the Schema
   Working Group, <URL:ftp://ds.internic.net/internet-drafts/draft-
   howes-x500-schema-02.txt>


Security Considerations

   Security considerations are not discussed in this memo.

Acknowledgments

   Paul-Andre Pays, Martijn Koster, Tim Howes, Rakesh Patel, and Russ
   Wright provided invaluable assistance in the creation of this
   document.




Smith                                                           [Page 3]


INTERNET-DRAFT      X.500 labeledURL Attribute Type      8 November 1994


Author's Address

   Mark Smith
   University of Michigan
   Information Technology Division
   535 W. William St.
   Ann Arbor, MI 48103-4943, USA

   Phone: +1 313 764-2277
   Fax:   +1 313 765-5140
   EMail: mcs@umich.edu


                This Internet Draft expires May 12th, 1995.





































Smith                                                           [Page 4]