---
schema_version: "1"
id: 9086151efff38146a995dee143ee15056ed6b26ef44ae42be1546270288e614c
title: Working with Custom Libraries
collection: admin
version: current
locale: en-us
portal_url: https://docs.salesforce.com/admin/current/en-us/platform/264-0-0/data_mask_and_seed_using_custom_libraries.md
canonical_url: https://help.salesforce.com/s/articleView?id=platform.data_mask_and_seed_using_custom_libraries.htm&release=264.0.0&type=5
source_site: help.salesforce.com
content_type: documentation
content_hash: 3a38d518a0cb2a625a4761bbd79237a0748a49e924147208eb257a6568706eba
description: Define new custom libraries, and edit existing custom libraries.
products:
  - Salesforce Platform
release: "264"
---
# Working with Custom Libraries

Define new custom libraries, and edit existing custom libraries.

### Required Editions

<table class="slds-table slds-table_bordered slds-max-medium-table_stacked slds-m-bottom_small edition"><colgroup><col></colgroup><tbody><tr class=""><td class="slds-cell-wrap" style="vertical-align:top;">Available in: Lightning Experience</td></tr><tr class=""><td class="slds-cell-wrap" style="vertical-align:top;">Available in: <strong>Professional</strong>, <strong>Enterprise</strong>, <strong>Unlimited</strong>, and <strong>Developer</strong> Editions with the Salesforce Data Mask add-on license.</td></tr></tbody></table>

![Note](https://sf-zdocs-cdn-prod.zoominsoftware.com/tdta-platform-deploy_sandboxes-264-0-0-production-enus/654e51d1-6795-49fe-bd43-b5385950cf4a/images/icon_note.png)

Note Data Mask & Seed and the Data Mask managed package share all custom libraries. Custom libraries created using either one of these apps are listed and available for use in the custom libraries page of the other app.

- **[Define New Custom Libraries](https://help.salesforce.com/s/articleView?id=platform.data_mask_and_seed_create_custom_library.htm&release=264.0.0&type=5)**  
    Create new custom libraries to add values to use to mask text or email fields in a masking policy.
- **[Edit Existing Custom Libraries](https://help.salesforce.com/s/articleView?id=platform.data_mask_and_seed_add_custom_libraries.htm&release=264.0.0&type=5)**  
    Add values or remove values used to mask text or email fields in a masking policy from custom libraries.