---
title: sn
description: X.500 surname attribute that contains the family name of a person.
component: pingds
version: 8.1
page_id: pingds:schemaref:at-sn
canonical_url: https://docs.pingidentity.com/pingds/8.1/schemaref/at-sn.html
---

# sn

X.500 `surname` attribute that contains the family name of a person.

|                             |                                                                                                                                                                                                                                                        |
| --------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| *OID*                       | 2.5.4.4                                                                                                                                                                                                                                                |
| *Names*                     | sn, surname                                                                                                                                                                                                                                            |
| *Superior type*             | [name](at-name.html)                                                                                                                                                                                                                                   |
| *Syntax*                    | [DirectoryString](s-DirectoryString.html)                                                                                                                                                                                                              |
| *Equality matching rule*    | [caseIgnoreMatch](mr-caseIgnoreMatch.html)                                                                                                                                                                                                             |
| *Ordering matching rule*    | [caseIgnoreOrderingMatch](mr-caseIgnoreOrderingMatch.html)                                                                                                                                                                                             |
| *Substring matching rule*   | [caseIgnoreSubstringsMatch](mr-caseIgnoreSubstringsMatch.html)                                                                                                                                                                                         |
| *Single value*              | false: multiple values allowed                                                                                                                                                                                                                         |
| *User modification allowed* | true                                                                                                                                                                                                                                                   |
| *Usage*                     | userApplications                                                                                                                                                                                                                                       |
| *Origin*                    | [RFC 4519](https://datatracker.ietf.org/doc/html/rfc4519)                                                                                                                                                                                              |
| *Schema file*               | 00-core.ldif                                                                                                                                                                                                                                           |
| *Used by*                   | [inetOrgPerson](oc-inetOrgPerson.html), [organizationalPerson](oc-organizationalPerson.html), [person](oc-person.html), [pilotPerson](oc-pilotPerson.html), [rFC822LocalPart](oc-rFC822LocalPart.html), [residentialPerson](oc-residentialPerson.html) |