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
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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].
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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]
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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.
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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]