---
sourceDocument: Australia Telecommunications Network Inventory
sourceDocumentLink: https://servicenow-prod.fluidtopics.net/r/telecom-network-inventory

 Release :

    - australia

ft:locale :

    - en-US

ft:publication_title :

    - Australia Telecommunications Network Inventory

ft:clusterId :

    - telninv

bundleId :

    - telninv

workflow :

    - Customer and Industry


---

# Extension point for custom name validation

# Extension point for custom name validation {#ariaid-title1}

Release version: Australia  
Updated September 10, 2026  
![](https://www.servicenow.com/docs/portal-asset/ico-clock) 1 minute to read  
The custom name validation extension point validates resolved names in the Inventory Template Overview tab. Administrators can register custom validation rules to enforce organization-specific naming
conventions, replacing or extending the default check.

## Extension point identity {#extension-point-custom-naming-validation__extension-point-identity}

The extension point is registered under the Network Inventory Core application:
{#extension-point-custom-naming-validation__extension-point-identity__entry__2}

| Field | Entries |
|-|-|
| Name | `TNINamingValidationBase` |
| API name | `sn_ni_core.TNINamingValidationBase` |
| Application | Network Inventory Core (`sn_ni_core`) |
[Table 1. Extension point details]

The extension point handles cross-sibling validation. It receives the set of related templates at one tree level and evaluates them as a group.

## Default validation rule {#extension-point-custom-naming-validation__default-validation-rule}

The TNI Naming Application includes a default validation rule registered against this extension point: the duplicate-name check described in [Name pattern validation](https://servicenow-prod.fluidtopics.net/F3MseOUzi5mOeZu7IW4e_A "Name pattern validation runs twice. It runs at save time to prevent errors. And it runs when the Overview tab loads the hierarchy to catch issues specific to template relationships."). The default rule flags two or more siblings whose patterns resolve to the same name.

The default rule appears in the Implementations table on the extension point record alongside any custom rules you register. An administrator can deactivate the default rule, replace it with a different rule, or leave it active and
add rules alongside it.

## Implementations {#extension-point-custom-naming-validation__implementations}

When the Inventory Template Overview tab refreshes, every active implementation of the extension point runs against the hierarchy. Each implementation receives an array of related templates at one tree level.
It examines the siblings under a single parent template according to its own rule and writes validation results back to any related template that fails.

After all implementations have run, their outputs appear in the Overview as follows:

* The error description of each implementation contributes to the Validation failed banner shown on the detail pane when a failed related template is selected. Descriptions from multiple implementations are concatenated in the banner, separated by `; `.
* The Error badge on the tree node is set by the last implementation that flagged the related template. Only one badge displays per node.
**Related concepts**   

* [Name pattern validation](https://servicenow-prod.fluidtopics.net/F3MseOUzi5mOeZu7IW4e_A "Name pattern validation runs twice. It runs at save time to prevent errors. And it runs when the Overview tab loads the hierarchy to catch issues specific to template relationships.")
* [Inventory template hierarchy view](https://servicenow-prod.fluidtopics.net/OS5FfXQqJRLARW~lpc5gSw "The Overview tab on an inventory template record shows the full template hierarchy as a tree. Use it to check resolved CI names and spot validation errors before deploying the template.")