---
schema_version: "1"
id: 1d2c93d231a5431067f9dd920aa1091d0925dc3189f2a7282048f242f3a3f543
title: Edit Existing 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_add_custom_libraries.md
canonical_url: https://help.salesforce.com/s/articleView?id=platform.data_mask_and_seed_add_custom_libraries.htm&release=264.0.0&type=5
source_site: help.salesforce.com
content_type: documentation
content_hash: d3fb36cee9a3dad399970620b2ab4630fdc35c548255d0cfe5541272e0613845
description: Add values or remove values used to mask text or email fields in a masking policy from custom libraries.
products:
  - Salesforce Platform
release: "264"
---
# Edit Existing Custom Libraries

Add values or remove values used to mask text or email fields in a masking policy from 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>

<table class="slds-table slds-table_bordered slds-max-medium-table_stacked slds-m-bottom_small permission">
        <colgroup>
          <col style="width:50%">
          <col style="width:50%">
        </colgroup>
        <thead class="slds-text-title_caps ">
          <tr class="">
            <th scope="colgroup" class="slds-cell-wrap" colspan="2" style="text-align:left;vertical-align:top;" id="d10817e74">User Permissions Needed</th>
          </tr>
        </thead>
        <tbody>
          <tr class="">
            <td data-label="User Permissions Needed" class="slds-cell-wrap" style="vertical-align:top;" headers="d10817e74 ">To edit custom libraries:</td>

            <td class="slds-cell-wrap" style="vertical-align:top;" headers="d10817e74 ">
              <ul>
                <li>Data Mask And Seed User Permission Set License</li>

                <li>Data Mask And Seed User Permission Set</li>

              </ul>
            </td>

          </tr>
        </tbody>
      </table>

In the Name column of the Custom Libraries page, click on a custom library name. The UI opens the custom library page in Edit mode.

- **[Manually Add Values to a Custom Library](https://help.salesforce.com/s/articleView?id=platform.data_mask_and_seed_add_to_custom_library.htm&release=264.0.0&type=5)**  
    Use this procedure when you want to individually add a relatively small number of typical or standard values to a custom library. For example, for QA of sandbox masking you only need a library containing 15 female first names.
- **[Generate and Add Values to a Custom Library with Einstein](https://help.salesforce.com/s/articleView?id=platform.data_mask_and_seed_add_to_custom_library_with_einstein.htm&release=264.0.0&type=5)**  
    Use this procedure when you want to generate and add to a custom library a large number of values of a specific or unique type. For example, for your QA of sandbox masking you need to generate a custom library containing 100 cities having a population of over 5 million.
- **[Delete Values from a Custom Library](https://help.salesforce.com/s/articleView?id=platform.data_mask_and_seed_delete_custom_library_values.htm&release=264.0.0&type=5)**  
    Use this procedure when you want to delete values from a custom library that are no longer necessary for or relevant to your development or QA work.