---
sourceDocument: Xanadu ServiceNow AI Platform Administration
sourceDocumentLink: https://servicenow-prod.fluidtopics.net/r/xanadu/platform-administration

 Release :

    - xanadu

ft:locale :

    - en-US

ft:publication_title :

    - Xanadu ServiceNow AI Platform Administration

ft:clusterId :

    - platadm

bundleId :

    - platadm

workflow :

    - Platform


---

# Define the reference key

# Define the reference key {#ariaid-title1}

* Release version: Xanadu
* 
* Updated August 1, 2024
* 
* ![](https://www.servicenow.com/docs/portal-asset/ico-clock) 1 minute to read

By default, reference fields store the sys_id of the record in the
database.

## Before you begin

Role required: personalize_dictionary

## About this task

By defining a reference key, you can identify a field other than sys_id to use as the
unique identifier for the reference field. The value of the reference key field,
instead of the sys_id, is stored in the database for that reference field.

## Procedure

1. Navigate to AllSystem DefinitionDictionary.
2. Open the field record (for example, resolved_by on the Incident table).
3. In the Reference key field, enter a field name on the referenced table (for example, email on the sys_user table).  
   Note:  
   Always choose a field from the referenced table that is both required and unique.
4. Select Update.

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