ISO/IEC 9594-6:2014

INTERNATIONAL ISO/IEC
STANDARD 9594-6
Seventh edition
2014-03-01
Information technology — Open Systems
Interconnection — The Directory —
Part 6:
Selected attribute types
Technologies de l'information — Interconnexion de systèmes ouverts
(OSI) — L'annuaire
Partie 6: Types d'attributs sélectionnés

Reference number
©
ISO/IEC 2014
©  ISO/IEC 2014
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ii © ISO/IEC 2014 – All rights reserved

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. In the field of information
technology, ISO and IEC have established a joint technical committee, ISO/IEC JTC 1.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of the joint technical committee is to prepare International Standards. Draft International
Standards adopted by the joint technical committee are circulated to national bodies for voting. Publication as
an International Standard requires approval by at least 75 % of the national bodies casting a vote.
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.
ISO/IEC 9594-6 was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology,
Subcommittee SC 6, Telecommunications and information exchange between systems, in collaboration with
ITU-T. The identical text is published as Rec. ITU-T X.520 (10/2012).
This seventh edition cancels and replaces the sixth edition (ISO/IEC 9594-6:2008), which has been
technically revised. It also incorporates the Technical Corrigenda ISO/IEC 9594-6:2008/Cor.1:2011,
ISO/IEC 9594-6:2008/Cor.2:2012 and ISO/IEC 9594-6:2008/Cor.3:2013.
ISO/IEC 9594 consists of the following parts, under the general title Information technology — Open Systems
Interconnection — The Directory:
— Part 1: Overview of concepts, models and services
— Part 2: Models
— Part 3: Abstract service definition
— Part 4: Procedures for distributed operation
— Part 5: Protocol specifications
— Part 6: Selected attribute types
— Part 7: Selected object classes
— Part 8: Public-key and attribute certificate frameworks
— Part 9: Replication
© ISO/IEC 2014 – All rights reserved

CONTENTS
Page
1 Scope . 1
2 Normative references . 1
2.1 Identical Recommendations | International Standards . 1
2.2 Other references . 2
2.3 ISO/IEC Standards . 3
3 Definitions . 3
4 Abbreviations . 3
5 Conventions . 3
6 Definition of selected attribute types . 5
6.1 System attribute types . 5
6.2 Labelling attribute types . 5
6.3 Geographical attribute types . 8
6.4 Organizational attribute types . 10
6.5 Explanatory attribute types . 11
6.6 Postal addressing attribute types . 13
6.7 Telecommunications addressing attribute types . 14
6.8 Preferences attribute types . 18
6.9 OSI application attribute types . 18
6.10 Relational attribute types . 19
6.11 Domain attribute types . 20
6.12 Hierarchical attribute types . 20
6.13 Attributes for applications using tag-based identification . 21
6.14 Notification attributes . 25
6.15 LDAP defined attribute types . 29
7 String preparation . 30
7.1 Transcode . 30
7.2 Map . 30
7.3 Normalize . 30
7.4 Prohibit . 30
7.5 Check bidi . 31
7.6 Insignificant Character Removal . 31
8 Definition of matching rules . 31
8.1 String matching rules . 31
8.2 Syntax-based matching rules . 34
8.3 Time matching rules . 37
8.4 First component matching rules . 38
8.5 Word matching rules . 39
8.6 Approximate Matching Rules . 42
8.7 Special Matching Rules . 42
8.8 Zonal Match . 42
8.9 uri Match . 45
8.10 LDAP defined matching rules . 46
9 Definition of syntaxes . 47
9.1 Directory syntaxes . 47
9.2 IETF syntaxes . 47
10 Definition of Context Types . 53
10.1 Language Context . 53
10.2 Temporal Context. 53
10.3 Locale Context . 57
10.4 LDAP Attribute Option Context . 57
Annex A – Selected attribute types in ASN.1 . 58
Rec. ITU-T X.520 (10/2012) iii

Page
Annex B – Summary of attribute types. 86
Annex C – Upper bounds . 87
Annex D – Alphabetical index of attributes, matching rules and contexts . 88
Annex E – Examples for zonal match matching rules . 90
Annex F – Mapping Object Identifiers and Uniform Resource Names into Distinguished Names . 92
F.1 Scope of this annex . 92
F.2 Object identifier resolution . 92
F.3 Uniform Resource Name (URN) resolution . 93
Annex G – Object identifier based Directory names . 96
G.1 Scope of annex . 96
G.2 Transformation of object identifiers into Directory names . 96
G.3 The use of object-identifier-based Directory names . 96
Annex H – Amendments and corrigenda . 98

iv Rec. ITU-T X.520 (10/2012)
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 types which may be found useful across a
range of applications of the Directory, as well as a number of standard attribute syntaxes and matching rules. One
particular use for many of the attributes defined herein is in the formation of names, particularly for the classes of
objects defined in Rec. ITU-T X.521 | ISO/IEC 9594-7.
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 seventh edition technically revises and
enhances the sixth edition of this Recommendation | International Standard.
This seventh edition specifies versions 1 and 2 of the Directory protocols.
The first and second editions specified only version 1. Most of the services and protocols specified in this edition are
designed to function under version 1. However some enhanced services and protocols, e.g., signed errors, will not
function unless all Directory entities involved in the operation have negotiated version 2. Whichever version has been
negotiated, differences between the services and between the protocols defined in the six editions, except for those
specifically assigned to version 2, are accommodated using the rules of extensibility defined in Rec. ITU-T X.519 |
ISO/IEC 9594-5.
Annex A, which is an integral part of this Recommendation | International Standard, provides the ASN.1 notation for
the complete module which defines the attributes, attribute syntaxes and matching rules.
Annex B, which is not an integral part of this Recommendation | International Standard, provides a table of attribute
types, for easy reference.
Annex C, which is not an integral part of this Recommendation | International Standard, provides an example of upper
bounds value constraints. These constraints are not reflected in these Directory Specifications, but are provided as a
reference for those implementations applying these constraints.
Annex D, which is not an integral part of this Recommendation | International Standard, lists alphabetically the
attributes and matching rules defined in this Directory Specification.
Annex E, which is not an integral part of this Recommendation | International Standard, gives examples relevant to the
definition of zonal matching.
Annex F, which is not an integral part of this Recommendation | International Standard, describes how a directory
distinguished name may be based on object identifiers and on Uniform Resource Names (URNs).
Annex G, which is not an integral part of this Recommendation | International Standard, describes an alternative way of
generating directory distinguished based on object identifiers. It contains information retrieved from Rec. ITU-T X.660 |
ISO/IEC 9834-1.
Annex H, 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.
Rec. ITU-T X.520 (10/2012) v
INTERNATIONAL STANDARD
RECOMMENDATION ITU-T
Information technology – Open Systems Interconnection –
The Directory: Selected attribute types
SECTION 1 – GENERAL
1 Scope
This Recommendation | International Standard defines a number of attribute types and matching rules which may be
found useful across a range of applications of the Directory.
Attribute types and matching rules fall into three categories, as described below.
Some attribute types and matching rules are used by a wide variety of applications or are understood and/or used by the
Directory itself.
NOTE 1 – It is recommended that an attribute type or matching rule defined in this Recommendation | International Standard be
used, in preference to the generation of a new one, whenever it is appropriate for the application.
NOTE 2 – The attribute and context types definitions by this Recommendation | International Standard have some associated
semantics. Such specifications should not be used in situations where these semantics do not apply.
Some attribute types and matching rules are internationally standardized, but are application-specific. These are defined
in the standards associated with the application concerned.
Any administrative authority can define its own attribute types and matching rules for any purpose. These are not
internationally standardized, and are available to others beyond the administrative authority which created them only
through bilateral agreement.
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
edition 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 (2012) | ISO/IEC 9594-1:2014, Information technology – Open Systems
Interconnection – The Directory: Overview of concepts, models and services.
– Recommendation ITU-T X.501 (2012) | ISO/IEC 9594-2:2014, Information technology – Open Systems
Interconnection – The Directory: Models.
– Recommendation ITU-T X.509 (2012) | ISO/IEC 9594-8:2014, Information technology – Open Systems
Interconnection – The Directory: Public-key and attribute certificate frameworks.
– Recommendation ITU-T X.511 (2012) | ISO/IEC 9594-3:2014, Information technology – Open Systems
Interconnection – The Directory: Abstract service definition.
– Recommendation ITU-T X.518 (2012) | ISO/IEC 9594-4:2014, Information technology – Open Systems
Interconnection – The Directory: Procedures for distributed operation.
– Recommendation ITU-T X.519 (2012) | ISO/IEC 9594-5:2014, Information technology – Open Systems
Interconnection – The Directory: Protocol specifications.
– Recommendation ITU-T X.521 (2012) | ISO/IEC 9594-7:2014, Information technology – Open Systems
Interconnection – The Directory: Selected object classes.
Rec. ITU-T X.520 (10/2012) 1
– Recommendation ITU-T X.525 (2012) | ISO/IEC 9594-9:2014, Information technology – Open Systems
Interconnection – The Directory: Replication.
– Recommendation ITU-T X.660 (2008) | ISO/IEC 9834-1:2008, Information technology – Open Systems
Interconnection – Procedures for the operation of OSI Registration Authorities: General procedures and
top arcs of the International Object Identifier tree.
– Recommendation ITU-T X.667 (2008) | ISO/IEC 9834-8:2008, Information technology – Open Systems
Interconnection – Procedures for the operation of OSI Registration Authorities: Generation and
registration of Universally Unique Identifiers (UUIDs) and their use as ASN.1 object identifier
components.
– Recommendation ITU-T X.668 (2008) | ISO/IEC 9834-9:2008, Information technology – Open Systems
Interconnection – Procedures for the operation of OSI Registration Authorities: Registration of object
identifier arcs for applications and services using tag-based identification.
– Recommendation ITU-T X.680 (2008) | ISO/IEC 8824-1:2008, Information technology – Abstract Syntax
Notation One (ASN.1): Specification of basic notation.
– Recommendation ITU-T X.681 (2008) | ISO/IEC 8824-2:2008, Information technology – Abstract Syntax
Notation One (ASN.1): Information object specification.
– Recommendation ITU-T X.682 (2008) | ISO/IEC 8824-3:2008, Information technology – Abstract Syntax
Notation One (ASN.1): Constraint specification.
– Recommendation ITU-T X.683 (2008) | ISO/IEC 8824-4:2008, Information technology – Abstract Syntax
Notation One (ASN.1): Parameterization of ASN.1 specifications.
2.2 Other references
– Recommendation ITU-T E.123 (2001), Notation for national and international telephone numbers, e-mail
addresses and web addresses.
– Recommendation ITU-T E.164 (2005), The international public telecommunication numbering plan.
– Recommendation ITU-T F.1 (1998), Operational provisions for the international public telegram service.
– Recommendation CCITT F.31 (1988), Telegram retransmission system.
– Recommendation CCITT F.401 (1992), Message handling services: Naming and addressing for public
message handling services.
– Recommendation ITU-T T.30 (2005), Procedures for document facsimile transmission in the general
switched telephone network.
– Recommendation ITU-T T.51 (1992), Latin based coded character sets for telematic services.
– Recommendation ITU-T T.62 (1993), Control procedures for teletex and Group 4 facsimile services.
– Recommendation ITU-T X.121 (2000), International numbering plan for public data networks.
– Recommendation ITU-T Y.2213 (2008), NGN service requirements and capabilities for network aspects
of applications and services using tag-based identification.
– ISO 3166-1:2006, Codes for the representation of names of countries and their subdivisions – Part 1:
Country codes.
– ISO 3166-3:1999, Codes for the representation of names of countries and their subdivisions – Part 3:
Code for formerly used names of countries.
– ISO 639-2:1998, Codes for the representation of names of languages – Part 2: Alpha-3 code.
– ISO/IEC/IEEE 9945:2009, Information technology – Portable Operating System Interface (POSIX) –
Base Specifications, Issue 7.
– ISO/IEC 15897:2001, Information technology – User interfaces – Procedures for the registration of
cultural elements.
– IETF RFC 3406 (2002), Uniform Resource Names (URN) Namespace Definition Mechanisms.
– IETF RFC 3454 (2003), Preparation of Internationalized Strings ("stringprep").
– IETF RFC 3641 (2003), Generic String Encoding Rules (GSER) for ASN.1 Types.
– IETF RFC 3642 (2003), Common Elements of Generic String Encoding Rules (GSER) Encodings.
– IETF RFC 3672 (2003), Subentries in the Lightweight Directory Access Protocol (LDAP).
– IETF RFC 3986 (2005), Uniform Resource Identifier (URI): Generic Syntax.
2 Rec. ITU-T X.520 (10/2012)
– IETF RFC 4510 (2006), Lightweight Directory Access Protocol (LDAP): Technical Specification Road
Map.
– IETF RFC 4512 (2006), Lightweight Directory Access Protocol (LDAP): Directory Information Models.
– IETF RFC 4514 (2006); Lightweight Directory Access Protocol (LDAP): String Representation of
Distinguished Names.
– IETF RFC 4517 (2006), Lightweight Directory Access Protocol (LDAP): Syntaxes and Matching Rules.
– IETF RFC 4519 (2006), Lightweight Directory Access Protocol (LDAP): Schema for User Applications.
– IETF RFC 4520 (2006), Internet Assigned Numbers Authority (IANA) Considerations for the Lightweight
Directory Access Protocol (LDAP).
– IETF RFC 4792 (2007), Encoding Instructions for the Generic String Encoding Rules (GSER).
– The Unicode Consortium. The Unicode Standard, Version 4.0.0, defined by: The Unicode Standard,
Version 4.0 (Reading, MA, Addison-Wesley, 2003. ISBN 0-321-18578-1).
– Unicode Standard Annex #15: Unicode Normalization Forms, by Mark Davis and Martin Dürst. An
integral part of The Unicode Standard, Version 4.0.
– National Imagery and Mapping Agency (NIMA): TR 8350.2, DoD Word Geodetic System 1984.
2.3 ISO/IEC Standards
– ISO/IEC 10646:2012, Information technology – Universal Coded Character Set (UCS).
3 Definitions
For the purposes of this Recommendation | International Standard, the following definitions apply:
The following terms are defined in Rec. ITU-T X.501 | ISO/IEC 9594-2:
a) attribute type;
b) context;
c) matching rule;
d) object class .
4 Abbreviations
For the purposes of this Recommendation | International Standard, the following abbreviations apply:
AFI Application Family Identifier
EPC Electronic Product Code
GSER Generic String Encoding Rules
LDAP Lightweight Directory Access Protocol
RFID Radio Frequency Identification
RDN Relative Distinguished Name
UII Unique Item Identifier
URL Uniform Resource Locator
URN Uniform Resource Name
UTM Universal Transverse Mercator
UUID Universally Unique Identifier
5 Conventions
The term "Directory Specification" (as in "this Directory Specification") shall be taken to mean Rec. ITU-T X.520 |
ISO/IEC 9594-6. The term "Directory Specifications" shall be taken to mean the X.500-series Recommendations and all
parts of ISO/IEC 9594.
Rec. ITU-T X.520 (10/2012) 3
This Directory Specification uses the term first edition systems to refer to systems conforming to the first edition of the
Directory Specifications, i.e., the 1988 edition of the series of CCITT X.500 Recommendations and the
ISO/IEC 9594:1990 edition.
This Directory Specification uses the term second edition systems to refer to systems conforming to the second edition of
the Directory Specifications, i.e., the 1993 edition of the series of ITU-T X.500 Recommendations and the
ISO/IEC 9594:1995 edition.
This Directory Specification uses the term third edition systems to refer to systems conforming to the third edition of the
Directory Specifications, i.e., the 1997 edition of the series of ITU-T X.500 Recommendations and the
ISO/IEC 9594:1998 edition.
This Directory Specification uses the term fourth edition systems to refer to systems conforming to the fourth edition of
the Directory Specifications, i.e., the 2001 editions of Recs ITU-T X.500, X.501, X.511, X.518, X.519, X.520, X.521,
X.525, and X.530, the 2000 edition of Rec. ITU-T X.509, and parts 1-10 of the ISO/IEC 9594:2001 edition.
This Directory Specification uses the term fifth edition systems to refer to systems conforming to the fifth edition of the
Directory Specifications, i.e., the 2005 edition of the series of ITU-T X.500 Recommendations and the
ISO/IEC 9594:2005 edition.
This Directory Specification uses the term sixth edition systems to refer to systems conforming to the sixth edition of the
Directory Specifications, i.e., the 2008 edition of the series of ITU-T X.500 Recommendations and the
ISO/IEC 9594:2008 edition.
This Directory Specification uses the term seventh edition systems to refer to systems conforming to the seventh edition
of these Directory Specifications, i.e., the 2012 edition of the series of ITU-T X.500 Recommendations and the
ISO/IEC 9594:2014 edition.
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
from normal text by displaying them in bold Times New Roman. Access control permissions are presented in italicized
Times New Roman.
If the items in a list are numbered (as opposed to using "–" or letters), then the items shall be considered steps in a
procedure.
Attribute types, matching rules and context types are defined in this Recommendation | International Standard by use of
the ATTRIBUTE, MATCHING-RULE and CONTEXT information object classes defined in Rec. ITU-T X.501 |
ISO/IEC 9594-2.
Examples of the use of the attribute types are described using an informal notation, where attribute type and value pairs
are represented by an acronym for the attribute type, followed by an equals sign ("="), followed by the example value for
the attribute.
4 Rec. ITU-T X.520 (10/2012)
SECTION 2 – SELECTED ATTRIBUTE TYPES
6 Definition of selected attribute types
This Directory Specification defines a number of attribute types which may be found useful across a range of
applications of the Directory.
Many of the attribute types defined in this Directory Specification are based on a common ASN.1 syntax:

UnboundedDirectoryString ::= CHOICE {
teletexString  TeletexString(SIZE (1.MAX)),
printableString PrintableString(SIZE (1.MAX)),
bmpString    BMPString(SIZE (1.MAX)),
universalString UniversalString(SIZE (1.MAX)),
uTF8String    UTF8String(SIZE (1.MAX)) }
A few attribute types are based on the following data type:

DirectoryString{INTEGER:maxSize} ::= CHOICE {
teletexString  TeletexString(SIZE (1.maxSize,.)),
printableString PrintableString(SIZE (1.maxSize,.)),
bmpString    BMPString(SIZE (1.maxSize,.)),
universalString UniversalString(SIZE (1.maxSize,.)),
uTF8String    UTF8String(SIZE (1.maxSize,.)) }
NOTE 1 – The above syntaxes are also used in other parts of these Directory Specifications.
NOTE 2 – The use of TeletexString is deprecated.
6.1 System attribute types
6.1.1 Knowledge Information
The Knowledge Information attribute type specifies a human readable accumulated description of knowledge mastered
by a specific DSA.
NOTE – This attribute is now obsolete.

knowledgeInformation ATTRIBUTE ::= {
WITH SYNTAX       UnboundedDirectoryString
EQUALITY MATCHING RULE  caseIgnoreMatch
OBSOLETE         TRUE
ID            id-at-knowledgeInformation }
6.2 Labelling attribute types
These attributes type are concerned with information about objects which has been explicitly associated with the objects
by a labelling process.
6.2.1 Name
The name attribute type is the attribute supertype from which string attribute types typically used for naming may be
formed.
name ATTRIBUTE ::= {
WITH SYNTAX       UnboundedDirectoryString
EQUALITY MATCHING RULE  caseIgnoreMatch
SUBSTRINGS MATCHING RULE caseIgnoreSubstringsMatch
LDAP-SYNTAX       directoryString.&id
LDAP-NAME        {"name"}
ID            id-at-name }
6.2.2 Common Name
An attribute of the type commonName specifies an identification of an object. A Common Name is not a directory name
in itself; it is a (possibly ambiguous) name by which the object is commonly known in some limited scope (such as an
organization) and conforms to the naming conventions of the country or culture with which it is associated.
An attribute value for Common Name is a string chosen by either the person or organization it describes or the
organization responsible for the object it describes for devices and application entities. For example, a typical name of a
Rec. ITU-T X.520 (10/2012) 5
person in an English-speaking country comprises a personal title (e.g., Mr., Ms., Rd, Professor, Sir, Lord), a first name,
middle name(s), last name, generation qualifier (if any, e.g., Jr.) and decorations and awards (if any, e.g., QC).
Examples
CN = "Mr. Robin Lachlan McLeod BSc(Hons) CEng MIEE";
CN = "Divisional Coordination Committee";
CN = "High Speed Modem".
Any variants should be associated with the named object as separate and alternative attribute values.
Other common variants should also be admitted, e.g., use of a middle name as a preferred first name; use of "Bill" in
place of "William", etc.
commonName ATTRIBUTE ::= {
SUBTYPE OF        name
WITH SYNTAX       UnboundedDirectoryString
LDAP-SYNTAX       directoryString.&id
LDAP-NAME        {"cn","commonName"}
ID            id-at-commonName }
6.2.3 Surname
An attribute of the type surname specifies the linguistic construct which normally is inherited by an individual from the
individual's parent or assumed by marriage, and by which the individual is commonly known.
An attribute value for Surname is a string, e.g., "McLeod".

surname ATTRIBUTE ::= {
SUBTYPE OF        name
WITH SYNTAX       UnboundedDirectoryString
LDAP-SYNTAX       directoryString.&id
LDAP-NAME        {"sn"}
ID            id-at-surname }
6.2.4 Given Name
The Given Name attribute type specifies the linguistic construct which is normally given to an individual by the
individual's parent, or is chosen by the individual, or by which the individual is commonly known.
An attribute value for Given Name is a string, e.g., "David" or "Jean-Paul".

givenName ATTRIBUTE ::= {
SUBTYPE OF        name
WITH SYNTAX       UnboundedDirectoryString
LDAP-SYNTAX       directoryString.&id
LDAP-NAME        {"givenName"}
ID            id-at-givenName }
6.2.5 Initials
The Initials attribute type contains the initials of some or all of an individual's names, but not the surname(s).
An attribute value for Initials is a string, e.g., "D" or "D." or "J.P.".

initials ATTRIBUTE ::= {
SUBTYPE OF        name
WITH SYNTAX       UnboundedDirectoryString
LDAP-SYNTAX       directoryString.&id
LDAP-NAME        {"initials"}
ID            id-at-initials }
6.2.6 Generation Qualifier
The Generation Qualifier attribute type contains a string which is used to provide generation information to qualify an
individual's name.
6 Rec. ITU-T X.520 (10/2012)
An attribute value for Generation Qualifier is a string, e.g., "Jr." or "II".

generationQualifier ATTRIBUTE ::= {
SUBTYPE OF        name
WITH SYNTAX       UnboundedDirectoryString
LDAP-SYNTAX       directoryString.&id
LDAP-NAME        {"generationQualifier"}
ID            id-at-generationQualifier }
6.2.7 Unique Identifier
The Unique Identifier attribute type specifies an identifier which may be used to distinguish between object references
when a distinguished name has been reused. It may be, for example, an encoded object identifier, certificate, date,
timestamp, or some other form of certification on the validity of the distinguished name.
An attribute value for Unique Identifier is a bit string.

uniqueIdentifier ATTRIBUTE ::= {
WITH SYNTAX       UniqueIdentifier
EQUALITY MATCHING RULE  bitStringMatch
LDAP-SYNTAX       bitString.&id
LDAP-NAME        {"x500UniqueIdentifier"}
ID            id-at-uniqueIdentifier }

UniqueIdentifier ::= BIT STRING
6.2.8 DN Qualifier
The DN Qualifier attribute type specifies disambiguating information to add to the relative distinguished name of an
entry. It is intended to be used for entries held in multiple DSAs which would otherwise have the same name, and that its
value be the same in a given DSA for all entries to which this information has been added.

dnQualifier ATTRIBUTE ::= {
WITH SYNTAX       PrintableString
EQUALITY MATCHING RULE  caseIgnoreMatch
ORDERING MATCHING RULE  caseIgnoreOrderingMatch
SUBSTRINGS MATCHING RULE caseIgnoreSubstringsMatch
LDAP-SYNTAX       printableString.&id
LDAP-NAME        {"dnQualifier"}
ID            id-at-dnQualifier }
6.2.9 Serial Number
The Serial Number attribute type specifies an identifier, the serial number of an object.
An attribute value for Serial Number is a printable string.

serialNumber ATTRIBUTE ::= {
WITH SYNTAX       PrintableString(SIZE (1.MAX))
EQUALITY MATCHING RULE  caseIgnoreMatch
SUBSTRINGS MATCHING RULE caseIgnoreSubstringsMatch
LDAP-SYNTAX       printableString.&id
LDAP-NAME        {"serialNumber"}
ID            id-at-serialNumber }
6.2.10 Pseudonym
The Pseudonym attribute type specifies a pseudonym for an object. It is used for naming an object when it is to be made
clear that its name is a pseudonym.

pseudonym ATTRIBUTE ::= {
SUBTYPE OF       name
WITH SYNTAX       UnboundedDirectoryString
ID           id-at-pseudonym }
6.2.11 Universal Unique Identifier Pair
The Universal Unique Identifier Pair attribute type specifies a pair of Universal Unique Identifiers (UUID), as specified
in Rec. ITU-T X.667 | ISO/IEC 9834-8. The pair collectively represents an issuer/subject relationship, the nature of
which is outside the scope of this Directory Specification. The initial UUID in the pair represents the issuer, and the
Rec. ITU-T X.520 (10/2012) 7
trailing UUID in the pair represents the subject of the issuer/subject relationship. An example of such a relationship is a
user account.
uUIDPair ATTRIBUTE ::= {
WITH SYNTAX       UUIDPair
EQUALITY MATCHING RULE uUIDPairMatch
ID           id-at-uuidpair }

UUIDPair ::= SEQUENCE {
issuerUUID  UUID,
subjectUUID UUID,
... }
UUID ::= OCTET STRING(SIZE (16)) -- UUID format only
6.2.12 uri
The uri attribute type is used for holding a Uniform Resource Identifier (URI) as defined in IETF RFC 3986.

uri ATTRIBUTE ::= {
WITH SYNTAX       URI
EQUALITY MATCHING RULE  uriMatch
LDAP-SYNTAX       directoryString.&id
LDAP-NAME        {"uri"}
ID            id-at-uri }

URI ::= UTF8String
6.2.13 URN
The URN attribute type is used for holding a Uniform Resource Name (URN) as defined in IETF RFC 3406.

urn ATTRIBUTE ::= {
SUBTYPE OF        uri
LDAP-SYNTAX       directoryString.&id
LDAP-NAME        {"urn"}
ID            id-at-urn }
6.2.14 URL
The URL attribute type is used for holding a Uniform Resource Locator (URL).

url ATTRIBUTE ::= {
SUBTYPE OF        uri
LDAP-SYNTAX       directoryString.&id
LDAP-NAME        {"url"}
ID            id-at-url }
6.3 Geographical attribute types
These attribute types are concerned with geographical positions or regions with which objects are associated.
6.3.1 Country Name
The Country Name attribute type specifies a country. When used as a component of a directory name, it identifies the
country in which the named object is physically located or with which it is associated in some other important way.
An attribute value for country name is a string chosen from ISO 3166-1 alpha-2 or ISO 3166-3 alpha-2.

countryName ATTRIBUTE ::= {
SUBTYPE OF        name
WITH SYNTAX       CountryName
SINGLE VALUE       TRUE
LDAP-SYNTAX       countryString.&id
LDAP-NAME        {"c"}
ID            id-at-countryName }

CountryName ::= PrintableString(SIZE (2)) -- ISO 3166 codes only
8 Rec. ITU-T X.520 (10/2012)
6.3.2 Locality Name
The Locality Name attribute type specifies a locality. When used as a component of a directory name, it identifies a
geographical area or locality in which the named object is physically located or with which it is associated in some other
important way.
An attribute value for Locality Name is a string, e.g., L = "Edinburgh".

localityName ATTRIBUTE ::= {
SUBTYPE OF        name
WITH SYNTAX       UnboundedDirectoryString
LDAP-SYNTAX       directoryString.&id
LDAP-NAME        {"l"}
ID            id-at-localityName }
The Collective Locality Name attribute type specifies a locality name for a collection of entries.

collectiveLocalityName ATTRIBUTE ::= {
SUBTYPE OF       localityName
COLLECTIVE       TRUE
ID           id-at-collectiveLocalityName }
6.3.3 State or Province Name
The State or Province Name attribute type specifies a state or province. When used as a component of a directory name,
it identifies a geographical subdivision in which the named object is physically located or with which it is associated in
some other important way.
An attribute value for State or Province Name is a string, e.g., S = "Ohio".

stateOrProvinceName ATTRIBUTE ::= {
SUBTYPE OF        name
WITH SYNTAX       UnboundedDirectoryString
LDAP-SYNTAX       directoryString.&id
LDAP-NAME        {"st"}
ID            id-at-stateOrProvinceName }
The Collective State or Province Name attribute type specifies a state or province name for a collection of entries.

collectiveStateOrProvinceName ATTRIBUTE ::= {
SUBTYPE OF       stateOrProvinceName
COLLECTIVE       TRUE
ID           id-at-collectiveStateOrProvinceName }
6.3.4 Street Address
The Street Address attribute type specifies a site for the local distribution and physical delivery in a postal address,
i.e., the street name, place, avenue and house number. When used as a component of a directory name, it identifies the
street address at which the named object is located or with which it is associated in some other important way.
An attribute value for Street Address is a string, e.g., "Arnulfstraße 60".

streetAddress ATTRIBUTE ::= {
WITH SYNTAX       UnboundedDirectoryString
EQUALITY MATCHING RULE  caseIgnoreMatch
SUBSTRINGS MATCHING RULE caseIgnoreSubstringsMatch
LDAP-SYNTAX       directoryString.&id
LDAP-NAME        {"street"}
ID            id-at-streetAddress
...