ISO/IEC 9594-6:2020/Amd 1:2025
(Amendment)Information technology — Open systems interconnection — Part 6: The Directory: Selected attribute types — Amendment 1
Information technology — Open systems interconnection — Part 6: The Directory: Selected attribute types — Amendment 1
Technologies de l'information — Interconnexion de systèmes ouverts (OSI) — Partie 6: Titre manque — Amendement 1
General Information
Relations
Standards Content (Sample)
International
Standard
ISO/IEC 9594-6
Ninth edition
Information technology — Open
2020-11
systems interconnection —
AMENDMENT 1
Part 6:
2025-05
The Directory: Selected
attribute types
AMENDMENT 1
Reference number
ISO/IEC 9594-6:2020/Amd. 1:2025(en) © ISO/IEC 2025
ISO/IEC 9594-6:2020/Amd. 1:2025(en)
© ISO/IEC 2025
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ISO/IEC 9594-6:2020/Amd. 1:2025(en)
Foreword
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This document was prepared by ITU-T as ITU-T X.520 (2019) Amd. 1 (10/2024) and drafted in
accordance with its editorial rules, in collaboration with Joint Technical Committee ISO/IEC JTC 1,
Information technology, Subcommittee SC 6, Telecommunications and information exchange
between systems.
A list of all parts in the ISO/IEC 9594 series can be found on the ISO and IEC websites.
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Rec. ITU-T X.520 (2019) Amd. 1 (10/2024)
© ISO/IEC 2025 – All rights reserved
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ISO/IEC 9594-6:2020/Amd. 1:2025(en)
INTERNATIONAL STANDARD ISO/IEC 9594-6
RECOMMENDATION ITU-T X.520
Information technology – Open Systems Interconnection – The Directory:
Selected attribute types
Amendment 1
Summary
Amendment 1 to Recommendation ITU-T X.520 (2019) | International Standard ISO/IEC 9594-6:2020, introduces text
updates to facilitate separation between cybersecurity ASN.1 modules and directory ASN.1 modules.
History
Edition Recommendation Approval Study Group Unique ID
1.0 ITU-T X.520 1988-11-25 11.1002/1000/3010
2.0 ITU-T X.520 1993-11-16 7 11.1002/1000/3011
3.0 ITU-T X.520 1997-08-09 7 11.1002/1000/4127
3.1 ITU-T X.520 (1997) Technical Cor. 1 2000-03-31 7 11.1002/1000/5042
3.2 ITU-T X.520 (1997) Amd. 1 2000-03-31 7 11.1002/1000/5041
3.3 ITU-T X.520 (1997) Technical Cor. 2 2001-02-02 7 11.1002/1000/5322
3.4 ITU-T X.520 (1997) Technical Cor. 3 2002-04-13 17 11.1002/1000/6027
4.0 ITU-T X.520 2001-02-02 7 11.1002/1000/5324
4.1 ITU-T X.520 (2001) Technical Cor. 1 2002-04-13 17 11.1002/1000/6028
4.2 ITU-T X.520 (2001) Technical Cor. 2 2005-11-29 17 11.1002/1000/8636
4.3 ITU-T X.520 (2001) Cor. 3 2008-05-29 17 11.1002/1000/9439
5.0 ITU-T X.520 2005-08-29 17 11.1002/1000/8508
5.1 ITU-T X.520 (2005) Cor. 1 2008-05-29 17 11.1002/1000/9440
5.2 ITU-T X.520 (2005) Cor. 2 2008-11-13 17 11.1002/1000/9628
5.3 ITU-T X.520 (2005) Cor. 3 2011-02-13 17 11.1002/1000/11050
5.4 ITU-T X.520 (2005) Cor. 4 2012-04-13 17 11.1002/1000/11590
6.0 ITU-T X.520 2008-11-13 17 11.1002/1000/9598
6.1 ITU-T X.520 (2008) Cor. 1 2011-02-13 17 11.1002/1000/11051
6.2 ITU-T X.520 (2008) Cor. 2 2012-04-13 17 11.1002/1000/11591
6.3 ITU-T X.520 (2008) Cor. 3 2012-10-14 17 11.1002/1000/11742
7.0 ITU-T X.520 2012-10-14 17 11.1002/1000/11743
7.1 ITU-T X.520 (2012) Cor. 1 2014-11-13 17 11.1002/1000/12350
8.0 ITU-T X.520 2016-10-14 17 11.1002/1000/13036
9.0 ITU-T X.520 2019-10-14 17 11.1002/1000/14037
9.1 ITU-T X.520 (2019) Amd. 1 2024-10-29 17 11.1002/1000/16176
To access the Recommendation, type the URL https://handle.itu.int/ in the address field of your web
browser, followed by the Recommendation's unique ID.
Rec. ITU-T X.520 (2019) Amd. 1 (10/2024)
© ISO/IEC 2025 – All rights reserved
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ISO/IEC 9594-6:2020/Amd. 1:2025(en)
FOREWORD
The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of
telecommunications, and information and communication technologies (ICTs). The ITU Telecommunication
Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical,
operating and tariff questions and issuing Recommendations on them with a view to standardizing
telecommunications on a worldwide basis.
The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes
the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics.
The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1.
In some areas of information technology which fall within ITU-T's purview, the necessary standards are
prepared on a collaborative basis with ISO and IEC.
NOTE
In this Recommendation, the expression "Administration" is used for conciseness to indicate both a
telecommunication administration and a recognized operating agency.
Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain
mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the
Recommendation is achieved when all of these mandatory provisions are met. The words "shall" or some other
obligatory language such as "must" and the negative equivalents are used to express requirements. The use of
such words does not suggest that compliance with the Recommendation is required of any party.
INTELLECTUAL PROPERTY RIGHTS
ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve
the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or
applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of
the Recommendation development process.
As of the date of approval of this Recommendation, ITU had not received notice of intellectual property,
protected by patents/software copyrights, which may be required to implement this Recommendation.
However, implementers are cautioned that this may not represent the latest information and are therefore
strongly urged to consult the appropriate ITU-T databases available via the ITU-T website at
https://www.itu.int/ITU-T/ipr/.
ITU 2025
All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior
written permission of ITU.
Rec. ITU-T X.520 (2019) Amd. 1 (10/2024)
© ISO/IEC 2025 – All rights reserved
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ISO/IEC 9594-6:2020/Amd. 1:2025(en)
CONTENTS
Page
1) Clause 2.2 . 1
2) Clause 4 . 1
3) Clause 5 . 1
4) Clause 6 and its subclauses . 1
5) Clause 8 and its subclauses . 2
6) Clause 9 and its subclauses . 2
7) Clause 10 and its subclauses . 3
8) Annex A . 3
Rec. ITU-T X.520 (2019) Amd. 1 (10/2024)
© ISO/IEC 2025 – All rights reserved
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ISO/IEC 9594-6:2020/Amd. 1:2025(en)
INTERNATIONAL STANDARD
ITU-T RECOMMENDATION
Information technology – Open Systems Interconnection –
The Directory: Selected attribute types
Amendment 1
1) Clause 2.2
Add a new normative reference to clause 2.2:
– IETF RFC 4524 (2006), COSINE LDAP/X.500 Schema.
2) Clause 4
Add a new abbreviation in clause 4
DNS Domain Name System
3) Clause 5
Add the following paragraph to end of clause 5:
Some ASN.1 symbols have been moved from the SelectedAttributeTypes module (Annex A) to the
UsefulDefinitions module (Annex A of Rec. ITU-T X.501 | ISO/IEC 9594-2). However, in the main body of text
the locations of the specifications for these ASN.1 symbols are not changed as they still can be considered part of selected
attribute types as they are present in the SelectAttributeTypes module by being imported from the
UsefulDefinitions module.
4) Clause 6 and its subclauses
In clause 6 add after the ASN.1 specification for UnboundedDirectoryString:
NOTE 1 – After the ninth edition of this Directory Specification, the definition of this data type was placed in the
UsefulDefinitions module in Rec. ITU-T X.501 | ISO/IEC 9594-2 rather than in the SelectedAttributeTypes
module.
In clause 6 update NOTE numbering as required.
In clause 6.2.1, add after the ASN.1 specification for name:
NOTE – After the ninth edition of this Directory Specification, the definitions of the name attribute type and the id-at-name
object identifier were placed in the UsefulDefinitions module in Rec. ITU-T X.501 | ISO/IEC 9594-2 rather than in the
SelectedAttributeTypes module.
In clause 6.2.2, add after the ASN.1 specification for commonName:
NOTE – After the ninth edition of this Directory Specification, the definitions of the commonName attribute type and the id-
at-commonName object identifier were placed in the UsefulDefinitions module in Rec. ITU-T X.501 | ISO/IEC 9594-2
rather than in the SelectedAttributeTypes module.
In clause 6.2.15, add after the ASN.1 specification for dnsName:
NOTE 1 – After the ninth edition of this Directory Specification, the definitions of the dnsName attribute type and the id-at-
dnsName object identifier were placed in the UsefulDefinitions module in Rec. ITU-T X.501 | ISO/IEC 9594-2 rather than
in the SelectedAttributeTypes module.
In clause 6.2.15, update NOTE numbering as required.
In clause 6.2.18, add after the ASN.1 specification for objectIdentifier:
NOTE – After the ninth edition of this Directory Specification, the definitions of the objectIdentifier attribute type and the
id-at-objectIdentifier object identifier were placed in the UsefulDefinitions module in Rec. ITU-T X.501 |
ISO/IEC 9594-2 rather than in the SelectedAttributeTypes module.
In clause 6.9.1, add after the ASN.1 specification for PresentationAddress:
Rec. ITU-T X.520 (2019) Amd. 1 (10/2024)
© ISO/IEC 2025 – All rights reserved
ISO/IEC 9594-6:2020/Amd. 1:2025(en)
NOTE – After the ninth edition of this Directory Specification, the definition of this data type was placed in the
UsefulDefinitions module in Rec. ITU-T X.501 | ISO/IEC 9594-2 rather than in the SelectedAttributeTypes
module.
5) Clause 8 and its subclauses
In clause 8.1.1, add after the ASN.1 specification for caseIgnoreMatch:
NOTE – After the ninth edition of this Directory Specification, the definitions of the caseIgnoreMatch matching rule and the
id-mr-caseIgnoreMatch object identifier were placed in the UsefulDefinitions module in Rec. ITU-T X.501 |
ISO/IEC 9594-2 rather than in the SelectedAttributeTypes module.
In clause 8.1.3, add after the ASN.1 specification for caseIgnoreSubstringMatch:
NOTE 1 – After the ninth edition of this Directory Specification, the definitions of the caseIgnoreSubstringsMatch
matching rule and the id-mr-caseIgnoreSubstringsMatch object identifier were placed in the UsefulDefinitions
module in Rec. ITU-T X.501 | ISO/IEC 9594-2 rather than in the SelectedAttributeTypes module.
In clause 8.1.3, add after the ASN.1 specification for SubstringAssertion:
NOTE 2 – After the ninth edition of this Directory Specification, the definition of the SubstringAssertion data type was
placed in the UsefulDefinitions module in Rec. ITU-T X.501 |
...
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