Information technology — Open systems interconnection — Part 7: The Directory: Selected object classes

This document defines a number of object classes and name forms which may be found useful across a range of applications of the Directory. The definition of an object class involves listing a number of attribute types which are relevant to objects of that class. The definition of a name form involves naming the object class to which it applies and listing the attributes to be used in forming names for objects of that class. These definitions are used by the administrative authority which is responsible for the management of the directory information. Any administrative authority can define its own object classes or subclasses and name forms for any purpose. NOTE 1 ? Those definitions may or may not use the notation specified in Rec. ITU-T X.501 | ISO/IEC 9594-2. NOTE 2 ? It is recommended that an object class defined in this Recommendation | International Standard, or a subclass derived from one, or a name form defined in this Recommendation | International Standard, be used in preference to the generation of a new one, whenever the semantics is appropriate for the application. Administrative authorities may support some or all the selected object classes and name forms, and may also add additional ones. All administrative authorities shall support the object classes which the directory uses for its own purpose (the top, alias and Directory system agent (DSA) object classes).

Technologies de l'information — Interconnexion de systèmes ouverts (OSI) — Partie 7: Titre manque

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Status
Published
Publication Date
30-Nov-2020
Current Stage
6060 - International Standard published
Start Date
30-Nov-2020
Due Date
19-Dec-2022
Completion Date
01-Dec-2020
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INTERNATIONAL ISO/IEC
STANDARD 9594-7
Ninth edition
2020-11
Information technology — Open
systems interconnection —
Part 7:
The Directory: Selected object classes
Reference number
ISO/IEC 9594-7:2020(E)
©
ISO/IEC 2020

---------------------- Page: 1 ----------------------
ISO/IEC 9594-7:2020(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO/IEC 2020
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO/IEC 2020 – All rights reserved

---------------------- Page: 2 ----------------------
ISO/IEC 9594-7:2020(E)
Foreword
ISO (the International Organization for Standardization) and IEC (the International Electrotechnical
Commission) form the specialized system for worldwide standardization. National bodies that are
members of ISO or IEC participate in the development of International Standards through technical
committees established by the respective organization to deal with particular fields of technical activity.
ISO and IEC technical committees collaborate in fields of mutual interest. Other international
organizations, governmental and non-governmental, in liaison with ISO and IEC, also take part in the
work.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of document should be noted (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO and IEC shall not be held responsible for identifying any or all such patent rights. Details
of any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents) or the IEC list of patent
declarations received (see http://patents.iec.ch).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the World
Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT),
see www.iso.org/iso/foreword.html.
This document was prepared by ITU-T as ITU-T X.521 (10/2019) 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.
This ninth edition cancels and replaces the eighth edition (ISO/IEC 9594-7:2017), which has been
technically revised.
A list of all parts in the ISO/IEC 9594 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body.
A complete listing of these bodies can be found at www.iso.org/members.html.
© ISO/IEC 2020 – All rights reserved iii

---------------------- Page: 3 ----------------------
ISO/IEC 9594-7:2020 (E)
CONTENTS
Page
SECTION 1 – GENERAL . 1
1 Scope . 1
2 Normative references. 1
2.1 Identical Recommendations | International Standards . 1
3 Definitions . 2
3.1 Communication Model definitions . 2
3.2 Directory Model definitions . 2
4 Conventions . 2
SECTION 2 – SELECTED OBJECT CLASSES . 4
5 Definition of useful attribute sets . 4
5.1 Telecommunication attribute set . 4
5.2 Postal attribute set . 4
5.3 Locale attribute set . 4
5.4 Organizational attribute set . 5
6 Definition of selected object classes . 5
6.1 Country . 5
6.2 Locality . 5
6.3 Organization . 5
6.4 Organizational Unit . 5
6.5 Person . 6
6.6 Organizational Person . 6
6.7 Organizational Role. 6
6.8 Group Of Names . 6
6.9 Group Of Unique Names . 7
6.10 Residential Person . 7
6.11 Application Process . 7
6.12 Application Entity . 7
6.13 DSA . 8
6.14 Device . 8
6.15 Strong Authentication User . 8
6.16 User Security Information . 8
6.17 User Password . 9
6.18 Certification Authority . 9
6.19 Certification Authority-V2 . 9
6.20 DMD . 9
6.21 OID Obj1 . 9
6.22 OID Obj2 . 10
6.23 OID ObjC . 10
6.24 OID root . 10
6.25 OID arc . 10
6.26 URN ObjC . 10
6.27 ISO Tag Information . 10
6.28 ISO Tag Type . 11
6.29 EPC Tag Information object class . 11
6.30 EPC Tag Type Object Class . 11
SECTION 3 – SELECTED NAME FORMS . 12
7 Definition of selected name forms . 12
7.1 Country name form . 12
7.2 Locality name form . 12
7.3 State Or Province name form . 12
7.4 Organization name form . 12
© ISO/IEC 2020 – All rights reserved
Rec. ITU-T X.521 (10/2019) v

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ISO/IEC 9594-7:2020 (E)
Page
7.5 Organizational Unit name form . 12
7.6 Person name form . 13
7.7 Organizational Person name form . 13
7.8 Organizational Role name form . 13
7.9 Group Of Names name form . 13
7.10 Residential Person name form . 13
7.11 Application Process name form . 13
7.12 Application Entity name form . 13
7.13 DSA name form . 14
7.14 Device name form . 14
7.15 DMD name form . 14
7.16 OIDC1 name form . 14
7.17 OIDC2 name form . 14
7.18 OIDC name form . 14
7.19 URNC name form . 14
7.20 OID root name form . 15
7.21 OID arc name form . 15
Annex A – Selected object classes and name forms in ASN.1 . 16
Annex B – Suggested name forms and Directory information tree (DIT) structures . 24
B.1 Country . 24
B.2 Organization . 25
B.3 Locality . 25
B.4 Organizational Unit . 25
B.5 Organizational Person . 26
B.6 Organizational Role. 26
B.7 Group of Names . 26
B.8 Residential Person . 27
B.9 Application Entity . 27
B.10 Device . 27
B.11 Application Process . 27
B.12 Alternative Structure Rule for Locality . 27
Annex C – Amendments and corrigenda . 29
Bibliography . 30
© ISO/IEC 2020 – All rights reserved
vi Rec. ITU-T X.521 (10/2019)

---------------------- Page: 5 ----------------------
ISO/IEC 9594-7:2020 (E)
Introduction
This Recommendation | International Standard, together with other Recommendations | International Standards, has been
produced to facilitate the interconnection of information processing systems to provide directory services. A set of such
systems, together with the directory information that they hold, can be viewed as an integrated whole, called the Directory.
The information held by the Directory, collectively known as the Directory Information Base (DIB), is typically used to
facilitate communication between, with or about objects such as application entities, people, terminals, and distribution
lists.
The Directory plays a significant role in Open Systems Interconnection, whose aim is to allow, with a minimum of
technical agreement outside of the interconnection standards themselves, the interconnection of information processing
systems:
– from different manufacturers;
– under different managements;
– of different levels of complexity; and
– of different ages.
This Recommendation | International Standard defines a number of attribute sets and object classes which may be found
useful across a range of applications of the Directory.
This Recommendation | International Standard provides the foundation frameworks upon which industry profiles can be
defined by other standards groups and industry forums. Many of the features defined as optional in these frameworks may
be mandated for use in certain environments through profiles. This ninth edition technically revises and enhances the
eighth edition of this Recommendation | International Standard.
Annex A, which is an integral part of this Recommendation | International Standard, provides an ASN.1 module
containing all of the type and value definitions which appear in this Recommendation | International Standard.
Annex B, which is not an integral part of this Recommendation | International Standard, provides some common naming
and structure rules which may or may not be used by administrative authorities.
Annex C, which is not an integral part of this Recommendation | International Standard, lists the amendments and defect
reports that have been incorporated to form this edition of this Recommendation | International Standard.
© ISO/IEC 2020 – All rights reserved
Rec. ITU-T X.521 (10/2019) vii

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ISO/IEC 9594-7:2020 (E)
INTERNATIONAL STANDARD
RECOMMENDATION ITU-T
Information technology – Open Systems Interconnection –
The Directory: Selected object classes
SECTION 1 – GENERAL
1 Scope
This Recommendation | International Standard defines a number of object classes and name forms which may be found
useful across a range of applications of the Directory. The definition of an object class involves listing a number of
attribute types which are relevant to objects of that class. The definition of a name form involves naming the object class
to which it applies and listing the attributes to be used in forming names for objects of that class. These definitions are
used by the administrative authority which is responsible for the management of the directory information.
Any administrative authority can define its own object classes or subclasses and name forms for any purpose.
NOTE 1 – Those definitions may or may not use the notation specified in Rec. ITU-T X.501 | ISO/IEC 9594-2.
NOTE 2 – It is recommended that an object class defined in this Recommendation | International Standard, or a subclass derived
from one, or a name form defined in this Recommendation | International Standard, be used in preference to the generation of a
new one, whenever the semantics is appropriate for the application.
Administrative authorities may support some or all the selected object classes and name forms, and may also add
additional ones.
All administrative authorities shall support the object classes which the directory uses for its own purpose (the top, alias
and Directory system agent (DSA) object classes).
2 Normative references
The following Recommendations and International Standards contain provisions which, through reference in this text,
constitute provisions of this Recommendation | International Standard. At the time of publication, the editions indicated
were valid. All Recommendations and Standards are subject to revision, and parties to agreements based on this
Recommendation | International Standard are encouraged to investigate the possibility of applying the most recent editions
of the Recommendations and Standards listed below. Members of IEC and ISO maintain registers of currently valid
International Standards. The Telecommunication Standardization Bureau of the ITU maintains a list of currently valid
ITU-T Recommendations.
2.1 Identical Recommendations | International Standards
– Recommendation ITU-T X.200 (1994) | ISO/IEC 7498-1:1994, Information technology – Open Systems
Interconnection – Basic Reference Model: The Basic Model.
– Recommendation ITU-T X.500 (2019) | ISO/IEC 9594-1:2020, Information technology – Open Systems
Interconnection – The Directory: Overview of concepts, models and services.
– Recommendation ITU-T X.501 (2019) | ISO/IEC 9594-2:2020, Information technology – Open Systems
Interconnection – The Directory: Models.
– Recommendation ITU-T X.509 (2019) | ISO/IEC 9594-8:2020, Information technology – Open Systems
Interconnection – The Directory: Public-key and attribute certificate frameworks.
– Recommendation ITU-T X.511 (2019) | ISO/IEC 9594-3:2020, Information technology – Open Systems
Interconnection – The Directory: Abstract service definition.
– Recommendation ITU-T X.518 (2019) | ISO/IEC 9594-4:2020, Information technology – Open Systems
Interconnection – The Directory: Procedures for distributed operation.
– Recommendation ITU-T X.519 (2019) | ISO/IEC 9594-5:2020, Information technology – Open Systems
Interconnection – The Directory: Protocol specifications.
– Recommendation ITU-T X.520 (2019) | ISO/IEC 9594-6:2020, Information technology – Open Systems
Interconnection – The Directory: Selected attribute types.
– Recommendation ITU-T X.525 (2019) | ISO/IEC 9594-9:2020, Information technology – Open Systems
Interconnection – The Directory: Replication.
© ISO/IEC 2020 – All rights reserved
Rec. ITU-T X.521 (10/2019) 1

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ISO/IEC 9594-7:2020 (E)
– Recommendation ITU-T X.680 (2015) | ISO/IEC 8824-1:2015, Information technology – Abstract Syntax
Notation One (ASN.1): Specification of basic notation.
– Recommendation ITU-T X.681 (2015) | ISO/IEC 8824-2:2015, Information technology – Abstract Syntax
Notation One (ASN.1): Information object specification.
– Recommendation ITU-T X.682 (2015) | ISO/IEC 8824-3:2015, Information technology – Abstract Syntax
Notation One (ASN.1): Constraint specification.
– Recommendation ITU-T X.683 (2015) | ISO/IEC 8824-4:2015, Information technology – Abstract Syntax
Notation One (ASN.1): Parameterization of ASN.1 specifications.
– Recommendation ITU-T X.690 (2015) | ISO/IEC 8825-1:2015, Information technology – ASN.1 encoding
rules: Specification of Basic Encoding Rules (BER), Canonical Encoding Rules (CER) and Distinguished
Encoding Rules (DER).
3 Definitions
For the purposes of this Recommendation | International Standard, the following definitions apply.
3.1 Communication Model definitions
The following terms are defined in Rec. ITU-T X.519 | ISO/IEC 9594-5:
a) application-entity;
b) application process.
3.2 Directory Model definitions
The following terms are defined in Rec. ITU-T X.501 | ISO/IEC 9594-2:
a) attribute;
b) attribute type;
c) Directory information tree (DIT);
d) Directory system agent (DSA);
e) attribute set;
f) entry;
g) name;
h) object class;
i) subclass;
j) name form;
k) structure rule.
4 Conventions
The term "Directory Specification" (as in "this Directory Specification") shall be taken to mean Rec. ITU-T X.521 |
ISO/IEC 9594-7. The term "Directory Specifications" shall be taken to mean the Rec. ITU-T X.500 | ISO/IEC 9594-1,
Rec. ITU-T X.501 | ISO/IEC 9594-2, Rec. ITU-T X.511 | ISO/IEC 9594-3, Rec. ITU-T X.518 | ISO/IEC 9594-4,
Rec. ITU-T X.519 | ISO/IEC 9594-5, Rec. ITU-T X.520 | ISO/IEC 9594-6, Rec. ITU-T X.521 | ISO/IEC 9594-7 and
Rec. ITU-T X.525 | ISO/IEC 9594-9.
If an International Standard or ITU-T Recommendation is referenced within normal text without an indication of the
edition, the edition shall be taken to be the latest one as specified in the normative references clause.
This Directory Specification makes extensive use of Abstract Syntax Notation One (ASN.1) for the formal specification
of data types and values, as it is specified in Rec. ITU-T X.680 | ISO/IEC 8824-1, ITU-T X.681 | ISO/IEC 8824-2, ITU-T
X.682 | ISO/IEC 8824-3, ITU-T X.683 | ISO/IEC 8824-4 and Rec. ITU-T X.690 | ISO/IEC 8825-1.
This Directory Specification presents ASN.1 notation in the bold Courier New typeface. When ASN.1 types and values
are referenced in normal text, they are differentiated from normal text by presenting them in the bold Courier New
typeface. The names of procedures, typically referenced when specifying the semantics of processing, are differentiated
© ISO/IEC 2020 – All rights reserved
2 Rec. ITU-T X.521 (10/2019)

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ISO/IEC 9594-7:2020 (E)
from normal text by displaying them in bold Times New Roman. Access control permissions are presented in italicized
Times New Roman.
Object classes and name forms are defined in this Directory Specification as values of the OBJECT-CLASS and
NAME-FORM information object classes defined in Rec. ITU-T X.501 | ISO/IEC 9594-2.

© ISO/IEC 2020 – All rights reserved
 Rec. ITU-T X.521 (10/2019) 3

---------------------- Page: 9 ----------------------
ISO/IEC 9594-7:2020 (E)
SECTION 2 – SELECTED OBJECT CLASSES
5 Definition of useful attribute sets
5.1 Telecommunication attribute set
This set of attributes is used to define those which are commonly used for business communications.

TelecommunicationAttributeSet ATTRIBUTE ::=
 {facsimileTelephoneNumber |
  internationalISDNNumber |
  telephoneNumber |
-- teletexTerminalIdentifier (Attribute type has been deleted)
-- teletexTerminalIdentifier | Attribute type has been deleted
  telexNumber |
  preferredDeliveryMethod |
  destinationIndicator |
  registeredAddress |
  x121Address}
5.2 Postal attribute set
This set of attributes is used to define those which are directly associated with postal delivery.

PostalAttributeSet ATTRIBUTE ::=
 {physicalDeliveryOfficeName |
  postalAddress |
  postalCode |
  postOfficeBox |
  streetAddress}
5.3 Locale attribute set
This set of attributes is used to define those which are commonly used for search purposes to indicate the locale of an
object.

LocaleAttributeSet ATTRIBUTE ::=
 {localityName |
  stateOrProvinceName |
  streetAddress}
© ISO/IEC 2020 – All rights reserved
4 Rec. ITU-T X.521 (10/2019)

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ISO/IEC 9594-7:2020 (E)
5.4 Organizational attribute set
This set of attributes is used to define the attributes that an organization or organizational unit may typically possess.

OrganizationalAttributeSet ATTRIBUTE ::=
 {description |
  LocaleAttributeSet |
  PostalAttributeSet |
  TelecommunicationAttributeSet |
  businessCategory |
  seeAlso |
  searchGuide |
  userPassword}
6 Definition of selected object classes
6.1 Country
The345u country object class is used to define country entries in the DIT.

country OBJECT-CLASS ::= {
 SUBCLASS OF  {top}
 MUST CONTAIN {countryName}
 MAY CONTAIN  {description |
         searchGuide}
 LDAP-NAME   {"country"}
 ID      id-oc-country }
6.2 Locality
The locality object class is used to define locality in the DIT.

locality OBJECT-CLASS ::= {
 SUBCLASS OF {top}
 MAY CONTAIN {description |
        searchGuide |
        LocaleAttributeSet |
        seeAlso}
 LDAP-NAME  {"locality"}
 ID      id-oc-locality }
At least one of Locality Name or State or Province Name shall be present.
6.3 Organization
The organization object class is used to define organization entries in the DIT.

organization OBJECT-CLASS ::= {
 SUBCLASS OF  {top}
 MUST CONTAIN {organizationName}
 MAY CONTAIN  {OrganizationalAttributeSet}
 LDAP-NAME   {"organization"}
 ID      id-oc-organization }
6.4 Organizational Unit
The organizationalUnit object class is used to define entries representing subdivisions of organizations.

organizationalUnit OBJECT-CLASS ::= {
 SUBCLASS OF  {top}
 MUST CONTAIN {organizationalUnitName}
 MAY CONTAIN  {OrganizationalAttributeSet}
 LDAP-NAME   {"organizationalUnit"}
 ID      id-oc-organizationalUnit }
© ISO/IEC 2020 – All rights reserved
 Rec. ITU-T X.521 (10/2019) 5

---
...

INTERNATIONAL ISO/IEC
STANDARD 9594-7
Ninth edition
Information technology — Open
systems interconnection —
Part 7:
The Directory: Selected object classes
PROOF/ÉPREUVE
Reference number
ISO/IEC 9594-7:2020(E)
©
ISO/IEC 2020

---------------------- Page: 1 ----------------------
ISO/IEC 9594-7:2020(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO/IEC 2020
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii PROOF/ÉPREUVE © ISO/IEC 2020 – All rights reserved

---------------------- Page: 2 ----------------------
ISO/IEC 9594-7:2020(E)
Foreword
ISO (the International Organization for Standardization) and IEC (the International Electrotechnical
Commission) form the specialized system for worldwide standardization. National bodies that are
members of ISO or IEC participate in the development of International Standards through technical
committees established by the respective organization to deal with particular fields of technical activity.
ISO and IEC technical committees collaborate in fields of mutual interest. Other international
organizations, governmental and non-governmental, in liaison with ISO and IEC, also take part in the
work.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of document should be noted (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO and IEC shall not be held responsible for identifying any or all such patent rights. Details
of any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents) or the IEC list of patent
declarations received (see http://patents.iec.ch).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the World
Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT),
see www.iso.org/iso/foreword.html.
This document was prepared by ITU-T as ITU-T X.521 (10/2019) and drafted in accordance with its
editorial rules. It was adopted by 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 website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

© ISO/IEC 2020 – All rights reserved iii

---------------------- Page: 3 ----------------------
ISO/IEC 9594-7:2020 (E)
CONTENTS
Page
SECTION 1 – GENERAL . 1
1 Scope . 1
2 Normative references. 1
2.1 Identical Recommendations | International Standards . 1
3 Definitions . 2
3.1 Communication Model definitions . 2
3.2 Directory Model definitions . 2
4 Conventions . 2
SECTION 2 – SELECTED OBJECT CLASSES . 4
5 Definition of useful attribute sets . 4
5.1 Telecommunication attribute set . 4
5.2 Postal attribute set . 4
5.3 Locale attribute set . 4
5.4 Organizational attribute set . 5
6 Definition of selected object classes . 5
6.1 Country . 5
6.2 Locality . 5
6.3 Organization . 5
6.4 Organizational Unit . 5
6.5 Person . 6
6.6 Organizational Person . 6
6.7 Organizational Role. 6
6.8 Group Of Names . 6
6.9 Group Of Unique Names . 7
6.10 Residential Person . 7
6.11 Application Process . 7
6.12 Application Entity . 7
6.13 DSA . 8
6.14 Device . 8
6.15 Strong Authentication User . 8
6.16 User Security Information . 8
6.17 User Password . 9
6.18 Certification Authority . 9
6.19 Certification Authority-V2 . 9
6.20 DMD . 9
6.21 OID Obj1 . 9
6.22 OID Obj2 . 10
6.23 OID ObjC . 10
6.24 OID root . 10
6.25 OID arc . 10
6.26 URN ObjC . 10
6.27 ISO Tag Information . 10
6.28 ISO Tag Type . 11
6.29 EPC Tag Information object class . 11
6.30 EPC Tag Type Object Class . 11
SECTION 3 – SELECTED NAME FORMS . 12
7 Definition of selected name forms . 12
7.1 Country name form . 12
7.2 Locality name form . 12
7.3 State Or Province name form . 12
7.4 Organization name form . 12
© ISO/IEC 2020 – All rights reserved
Rec. ITU-T X.521 (10/2019) v

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ISO/IEC 9594-7:2020 (E)
Page
7.5 Organizational Unit name form . 12
7.6 Person name form . 13
7.7 Organizational Person name form . 13
7.8 Organizational Role name form . 13
7.9 Group Of Names name form . 13
7.10 Residential Person name form . 13
7.11 Application Process name form . 13
7.12 Application Entity name form . 13
7.13 DSA name form . 14
7.14 Device name form . 14
7.15 DMD name form . 14
7.16 OIDC1 name form . 14
7.17 OIDC2 name form . 14
7.18 OIDC name form . 14
7.19 URNC name form . 14
7.20 OID root name form . 15
7.21 OID arc name form . 15
Annex A – Selected object classes and name forms in ASN.1 . 16
Annex B – Suggested name forms and Directory information tree (DIT) structures . 24
B.1 Country . 24
B.2 Organization . 25
B.3 Locality . 25
B.4 Organizational Unit . 25
B.5 Organizational Person . 26
B.6 Organizational Role. 26
B.7 Group of Names . 26
B.8 Residential Person . 27
B.9 Application Entity . 27
B.10 Device . 27
B.11 Application Process . 27
B.12 Alternative Structure Rule for Locality . 27
Annex C – Amendments and corrigenda . 29
Bibliography . 30
© ISO/IEC 2020 – All rights reserved
vi Rec. ITU-T X.521 (10/2019)

---------------------- Page: 5 ----------------------
ISO/IEC 9594-7:2020 (E)
Introduction
This Recommendation | International Standard, together with other Recommendations | International Standards, has been
produced to facilitate the interconnection of information processing systems to provide directory services. A set of such
systems, together with the directory information that they hold, can be viewed as an integrated whole, called the Directory.
The information held by the Directory, collectively known as the Directory Information Base (DIB), is typically used to
facilitate communication between, with or about objects such as application entities, people, terminals, and distribution
lists.
The Directory plays a significant role in Open Systems Interconnection, whose aim is to allow, with a minimum of
technical agreement outside of the interconnection standards themselves, the interconnection of information processing
systems:
– from different manufacturers;
– under different managements;
– of different levels of complexity; and
– of different ages.
This Recommendation | International Standard defines a number of attribute sets and object classes which may be found
useful across a range of applications of the Directory.
This Recommendation | International Standard provides the foundation frameworks upon which industry profiles can be
defined by other standards groups and industry forums. Many of the features defined as optional in these frameworks may
be mandated for use in certain environments through profiles. This ninth edition technically revises and enhances the
eighth edition of this Recommendation | International Standard.
Annex A, which is an integral part of this Recommendation | International Standard, provides an ASN.1 module
containing all of the type and value definitions which appear in this Recommendation | International Standard.
Annex B, which is not an integral part of this Recommendation | International Standard, provides some common naming
and structure rules which may or may not be used by administrative authorities.
Annex C, which is not an integral part of this Recommendation | International Standard, lists the amendments and defect
reports that have been incorporated to form this edition of this Recommendation | International Standard.
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ISO/IEC 9594-7:2020 (E)
INTERNATIONAL STANDARD
RECOMMENDATION ITU-T
Information technology – Open Systems Interconnection –
The Directory: Selected object classes
SECTION 1 – GENERAL
1 Scope
This Recommendation | International Standard defines a number of object classes and name forms which may be found
useful across a range of applications of the Directory. The definition of an object class involves listing a number of
attribute types which are relevant to objects of that class. The definition of a name form involves naming the object class
to which it applies and listing the attributes to be used in forming names for objects of that class. These definitions are
used by the administrative authority which is responsible for the management of the directory information.
Any administrative authority can define its own object classes or subclasses and name forms for any purpose.
NOTE 1 – Those definitions may or may not use the notation specified in Rec. ITU-T X.501 | ISO/IEC 9594-2.
NOTE 2 – It is recommended that an object class defined in this Recommendation | International Standard, or a subclass derived
from one, or a name form defined in this Recommendation | International Standard, be used in preference to the generation of a
new one, whenever the semantics is appropriate for the application.
Administrative authorities may support some or all the selected object classes and name forms, and may also add
additional ones.
All administrative authorities shall support the object classes which the directory uses for its own purpose (the top, alias
and Directory system agent (DSA) object classes).
2 Normative references
The following Recommendations and International Standards contain provisions which, through reference in this text,
constitute provisions of this Recommendation | International Standard. At the time of publication, the editions indicated
were valid. All Recommendations and Standards are subject to revision, and parties to agreements based on this
Recommendation | International Standard are encouraged to investigate the possibility of applying the most recent editions
of the Recommendations and Standards listed below. Members of IEC and ISO maintain registers of currently valid
International Standards. The Telecommunication Standardization Bureau of the ITU maintains a list of currently valid
ITU-T Recommendations.
2.1 Identical Recommendations | International Standards
– Recommendation ITU-T X.200 (1994) | ISO/IEC 7498-1:1994, Information technology – Open Systems
Interconnection – Basic Reference Model: The Basic Model.
– Recommendation ITU-T X.500 (2019) | ISO/IEC 9594-1:2020, Information technology – Open Systems
Interconnection – The Directory: Overview of concepts, models and services.
– Recommendation ITU-T X.501 (2019) | ISO/IEC 9594-2:2020, Information technology – Open Systems
Interconnection – The Directory: Models.
– Recommendation ITU-T X.509 (2019) | ISO/IEC 9594-8:2020, Information technology – Open Systems
Interconnection – The Directory: Public-key and attribute certificate frameworks.
– Recommendation ITU-T X.511 (2019) | ISO/IEC 9594-3:2020, Information technology – Open Systems
Interconnection – The Directory: Abstract service definition.
– Recommendation ITU-T X.518 (2019) | ISO/IEC 9594-4:2020, Information technology – Open Systems
Interconnection – The Directory: Procedures for distributed operation.
– Recommendation ITU-T X.519 (2019) | ISO/IEC 9594-5:2020, Information technology – Open Systems
Interconnection – The Directory: Protocol specifications.
– Recommendation ITU-T X.520 (2019) | ISO/IEC 9594-6:2020, Information technology – Open Systems
Interconnection – The Directory: Selected attribute types.
– Recommendation ITU-T X.525 (2019) | ISO/IEC 9594-9:2020, Information technology – Open Systems
Interconnection – The Directory: Replication.
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ISO/IEC 9594-7:2020 (E)
– Recommendation ITU-T X.680 (2015) | ISO/IEC 8824-1:2015, Information technology – Abstract Syntax
Notation One (ASN.1): Specification of basic notation.
– Recommendation ITU-T X.681 (2015) | ISO/IEC 8824-2:2015, Information technology – Abstract Syntax
Notation One (ASN.1): Information object specification.
– Recommendation ITU-T X.682 (2015) | ISO/IEC 8824-3:2015, Information technology – Abstract Syntax
Notation One (ASN.1): Constraint specification.
– Recommendation ITU-T X.683 (2015) | ISO/IEC 8824-4:2015, Information technology – Abstract Syntax
Notation One (ASN.1): Parameterization of ASN.1 specifications.
– Recommendation ITU-T X.690 (2015) | ISO/IEC 8825-1:2015, Information technology – ASN.1 encoding
rules: Specification of Basic Encoding Rules (BER), Canonical Encoding Rules (CER) and Distinguished
Encoding Rules (DER).
3 Definitions
For the purposes of this Recommendation | International Standard, the following definitions apply.
3.1 Communication Model definitions
The following terms are defined in Rec. ITU-T X.519 | ISO/IEC 9594-5:
a) application-entity;
b) application process.
3.2 Directory Model definitions
The following terms are defined in Rec. ITU-T X.501 | ISO/IEC 9594-2:
a) attribute;
b) attribute type;
c) Directory information tree (DIT);
d) Directory system agent (DSA);
e) attribute set;
f) entry;
g) name;
h) object class;
i) subclass;
j) name form;
k) structure rule.
4 Conventions
The term "Directory Specification" (as in "this Directory Specification") shall be taken to mean Rec. ITU-T X.521 |
ISO/IEC 9594-7. The term "Directory Specifications" shall be taken to mean the Rec. ITU-T X.500 | ISO/IEC 9594-1,
Rec. ITU-T X.501 | ISO/IEC 9594-2, Rec. ITU-T X.511 | ISO/IEC 9594-3, Rec. ITU-T X.518 | ISO/IEC 9594-4,
Rec. ITU-T X.519 | ISO/IEC 9594-5, Rec. ITU-T X.520 | ISO/IEC 9594-6, Rec. ITU-T X.521 | ISO/IEC 9594-7 and
Rec. ITU-T X.525 | ISO/IEC 9594-9.
If an International Standard or ITU-T Recommendation is referenced within normal text without an indication of the
edition, the edition shall be taken to be the latest one as specified in the normative references clause.
This Directory Specification makes extensive use of Abstract Syntax Notation One (ASN.1) for the formal specification
of data types and values, as it is specified in Rec. ITU-T X.680 | ISO/IEC 8824-1, ITU-T X.681 | ISO/IEC 8824-2, ITU-T
X.682 | ISO/IEC 8824-3, ITU-T X.683 | ISO/IEC 8824-4 and Rec. ITU-T X.690 | ISO/IEC 8825-1.
This Directory Specification presents ASN.1 notation in the bold Courier New typeface. When ASN.1 types and values
are referenced in normal text, they are differentiated from normal text by presenting them in the bold Courier New
typeface. The names of procedures, typically referenced when specifying the semantics of processing, are differentiated
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ISO/IEC 9594-7:2020 (E)
from normal text by displaying them in bold Times New Roman. Access control permissions are presented in italicized
Times New Roman.
Object classes and name forms are defined in this Directory Specification as values of the OBJECT-CLASS and
NAME-FORM information object classes defined in Rec. ITU-T X.501 | ISO/IEC 9594-2.

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ISO/IEC 9594-7:2020 (E)
SECTION 2 – SELECTED OBJECT CLASSES
5 Definition of useful attribute sets
5.1 Telecommunication attribute set
This set of attributes is used to define those which are commonly used for business communications.

TelecommunicationAttributeSet ATTRIBUTE ::=
 {facsimileTelephoneNumber |
  internationalISDNNumber |
  telephoneNumber |
-- teletexTerminalIdentifier (Attribute type has been deleted)
-- teletexTerminalIdentifier | Attribute type has been deleted
  telexNumber |
  preferredDeliveryMethod |
  destinationIndicator |
  registeredAddress |
  x121Address}
5.2 Postal attribute set
This set of attributes is used to define those which are directly associated with postal delivery.

PostalAttributeSet ATTRIBUTE ::=
 {physicalDeliveryOfficeName |
  postalAddress |
  postalCode |
  postOfficeBox |
  streetAddress}
5.3 Locale attribute set
This set of attributes is used to define those which are commonly used for search purposes to indicate the locale of an
object.

LocaleAttributeSet ATTRIBUTE ::=
 {localityName |
  stateOrProvinceName |
  streetAddress}
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ISO/IEC 9594-7:2020 (E)
5.4 Organizational attribute set
This set of attributes is used to define the attributes that an organization or organizational unit may typically possess.

OrganizationalAttributeSet ATTRIBUTE ::=
 {description |
  LocaleAttributeSet |
  PostalAttributeSet |
  TelecommunicationAttributeSet |
  businessCategory |
  seeAlso |
  searchGuide |
  userPassword}
6 Definition of selected object classes
6.1 Country
The345u country object class is used to define country entries in the DIT.

country OBJECT-CLASS ::= {
 SUBCLASS OF  {top}
 MUST CONTAIN {countryName}
 MAY CONTAIN  {description |
         searchGuide}
 LDAP-NAME   {"country"}
 ID      id-oc-country }
6.2 Locality
The locality object class is used to define locality in the DIT.

locality OBJECT-CLASS ::= {
 SUBCLASS OF {top}
 MAY CONTAIN {description |
        searchGuide |
        LocaleAttributeSet |
        seeAlso}
 LDAP-NAME  {"locality"}
 ID      id-oc-locality }
At least one of Locality Name or State or Province Name shall be present.
6.3 Organization
The organization object class is used to define organization entries in the DIT.

organization OBJECT-CLASS ::= {
 SUBCLASS OF  {top}
 MUST CONTAIN {organizationName}
 MAY CONTAIN  {OrganizationalAttributeSet}
 LDAP-NAME   {"organization"}
 ID      id-oc-organization }
6.4 Organizational Unit
The organizationalUnit object class is used to define entries representing subdivisions of organizations.

organizationalUnit OBJECT-CLASS ::= {
 SUBCLASS OF  {top}
 MUST CONTAIN {organizationalUnitName}
 MAY CONTAIN  {OrganizationalAttributeSet}
 LDAP-NAME   {"organizationalUnit"}
 ID      id-oc-organizationalUnit }
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ISO/IEC 9594-7:2020 (E)
6.5 Person
The per
...

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