---
sourceDocument: Australia ServiceNow AI Platform Administration
sourceDocumentLink: https://www.servicenow.com/docs/r/platform-administration

 Release :

    - australia

ft:locale :

    - en-US

ft:publication_title :

    - Australia ServiceNow AI Platform Administration

ft:clusterId :

    - platadm

bundleId :

    - platadm

workflow :

    - Platform


---

# Define dictionary override

# Define a dictionary override {#ariaid-title1}

* Release version: Australia
* 
* Updated March 12, 2026
* 
* ![](https://www.servicenow.com/docs/portal-asset/ico-clock) 2 minutes to read

Use a dictionary override to allow a field in a child table to have a different value
or behavior than the same field in a parent table. For example, a dictionary override
changes the default value of the priority field from 4 in the parent table to 5 in the
Incident table.

## Before you begin

Role required: admin.

## About this task

Dictionary overrides are only available for tables that support [table
extension](https://www.servicenow.com/docs/0QyNypxW4jeUbkhOCyS8Ag "Enable one or more child tables to share fields and records with a parent table. Administrators and application developers can only extend tables during table creation.").

Dictionary overrides are inherited by extended tables, so it may be necessary to
define additional overrides to change the value of fields on extended tables. For
example, if you define the default value of cmdb_ci.install_status to be 3, and
create an override for the same field on cmdb_ci_hardware to be 5, all tables
extended from the Hardware table will also default to 5. So if you want the default
cmdb_ci_computer.install_status to be 3, you will need another override.

You can add a dictionary override in a scoped app, but you must add the override
while working in the scoped app context and you can only select child tables from
within that scope. Open the scoped app, edit the field's dictionary entry, add a
new dictionary override, select the child table, and then provide the override
details.

## Procedure

1. Navigate to AllSystem DefinitionDictionary.
2. Open the record for the field.
3. In the Dictionary Overrides related list, click New.
4. Fill in the fields on the form, as appropriate (see table).  
   {#t_DefineADictionaryOverride__simpletable_ph1_2hv_4q__entry__2}

   | Field | Description |
   |-|-|
   | Application | The application scope to which the record belongs. |
   | Base table | The parent table containing the field to override. |
   | Table | Select the extended table to which the dictionary override applies. Note: The list shows only tables and database views that are in the same scope as the dictionary override. |
   | Override reference qualifier | Select the check box to display the Reference qualifier field, which overrides the [Reference qualifiers](https://www.servicenow.com/docs/DlyLq3Nrg62ri6Ar_DVgWQ "Use reference qualifiers to filter the data that is returned for a reference field.") for the field on the extended table. |
   | Override dependent | Select the check box to display the Dependent field, which overrides the field on which the current field depends. |
   | Override attributes | Select the check box to display the Attributes field, which overrides the [dictionary attributes](https://www.servicenow.com/docs/9BDmpv90lMoB~WPAcCiiBg "Dictionary attributes alter the behavior of the table or field that the dictionary record describes. Administrators can add or modify dictionary attributes.") for the field on the extended table. Note: Any attributes defined on the base table are ignored. If there are attributes on the base table that should still apply to the extended table, make sure to include them in this field. |
   | Override default value | Select the check box to display the Default Value field, which overrides the default value for the field on the extended table. |
   | Override calculation | Select the check box to display the Calculation field, which overrides the calculation of the value for the field on the extended table. |
   | Override mandatory | Select the check box to display the Mandatory field, which overrides whether the field on the extended table must contain a value to save a record. |
   | Override read only | Select the check box to display the Read only field, which overrides whether a user can change the field value on the extended table. |
   | Override display value | Select the check box to use this field as the display value on the extended table. For example, the Story \[`rm_story`\] table uses the short description as the display value in reference fields instead of the number, as defined in the Task \[`task`\] table. Note: Only fields that exist at the task table can be used as display value overrides. |
   [Table 1. Dictionary overrides table fields]

   {#t_DefineADictionaryOverride__simpletable_ph1_2hv_4q}
5. Click Submit.

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