---
title: objectClasses
description: This operational attribute used in LDAP schema defines object classes, which specify the types of objects that an entry represents, and the required and optional attributes for entries of those types.
component: pingds
version: 7.3
page_id: pingds:schemaref:at-objectClasses
canonical_url: https://docs.pingidentity.com/pingds/8.1/schemaref/at-objectClasses.html
llms_txt: https://docs.pingidentity.com/pingds/llms.txt
docs_for_agents: https://developer.pingidentity.com/build-with-ai/docs-for-agents.md
superseded_by: https://docs.pingidentity.com/pingds/8.1/schemaref/at-objectClasses.html
---

# objectClasses

This operational attribute used in LDAP schema defines object classes, which specify the types of objects that an entry represents, and the required and optional attributes for entries of those types.

|                             |                                                                                    |
| --------------------------- | ---------------------------------------------------------------------------------- |
| *Single value*              | false: multiple values allowed                                                     |
| *Origin*                    | [RFC 4512](https://datatracker.ietf.org/doc/html/rfc4512)                          |
| *Usage*                     | directoryOperation                                                                 |
| *OID*                       | 2.5.21.6                                                                           |
| *User modification allowed* | true                                                                               |
| *Schema file*               | 00-core.ldif                                                                       |
| *Names*                     | objectClasses                                                                      |
| *Used by*                   | [subschema](oc-subschema.html)                                                     |
| *Syntax*                    | [ObjectClassDescription](s-ObjectClassDescription.html)                            |
| *Equality matching rule*    | [objectIdentifierFirstComponentMatch](mr-objectIdentifierFirstComponentMatch.html) |