ISO/IEC 9594-7:2020

Overview

ISO/IEC 9594-7:2020 - "Information technology - Open systems interconnection - Part 7: The Directory: Selected object classes" specifies a set of object classes, attribute sets and name forms intended for use across directory services. Published as the ninth edition and aligned with ITU‑T X.521, this part of the ISO/IEC 9594 series provides reusable directory building blocks, an ASN.1 module (Annex A) and suggested naming/DIT structures (Annex B) to help administrative authorities manage directory information consistently.

Key topics and requirements

• Object class definitions: Lists object classes such as Country, Locality, Organization, Organizational Unit, Person, Organizational Role, Group types, DSA, Device, Certification Authority and others, describing the attribute types relevant to each class.
• Name forms: Defines name forms that associate object classes with the attributes used to form distinguished names for those objects.
• Attribute sets: Introduces useful attribute sets (e.g., telecommunication, postal, locale, organizational) to promote consistent attribute usage.
• Administrative authority guidance: Administrative authorities may define custom object classes and name forms but are recommended to reuse the standard’s definitions where semantics match the application. All authorities must support the object classes used by the Directory itself (notably top, alias, and Directory System Agent (DSA)).
• ASN.1 module and examples: Annex A contains the ASN.1 module for type/value definitions; Annex B provides suggested naming rules and Directory Information Tree (DIT) structures; Annex C documents amendments incorporated in this edition.

Practical applications

• Building consistent directory schemas for enterprise directory services and identity repositories.
• Defining directory-enabled applications that require standard object semantics (people, devices, services, certification authorities).
• Serving as a baseline for industry profiles and interoperability agreements between organizations or vendors.
• Assisting implementers in generating interoperable DIT structures and ASN.1-based schema modules.

Who should use this standard

• Directory architects and schema designers
• Identity and access management (IAM) engineers
• System integrators and software developers implementing directory services
• PKI and certification authority operators (uses include Certification Authority object classes)
• Standards bodies and industry forums creating domain-specific directory profiles

Related standards

• ISO/IEC 9594 series (other parts of The Directory)
• ITU‑T X.521 (equivalent specification referenced in the document)

Keywords: ISO/IEC 9594-7:2020, The Directory, object classes, name forms, directory services, ASN.1, DIT, Directory Information Base, ITU‑T X.521.