---
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: 8.1
page_id: pingds:schemaref:at-objectClasses
canonical_url: 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.

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