# Frequently Asked Questions

# How can I make a custom read-only field with a default value appear only for a specific item type in Ketryx?

Rachel Grandmaison

- Updated 9 months ago

When you use the **Extra field names** setting in Ketryx, any field listed there (and with a value, such as a default) will appear in all Ketryx item records where data is present, regardless of the Jira screen association. This is because **Extra field names** does not allow you to restrict a field to specific item types.

To have a custom field appear only for certain item types, use the **Custom item fields configuration** and associate the field with specific item types under **Item fields**. This approach allows you to control both the field's editability and its association with item types in Ketryx, avoiding the global behavior of **Extra field names**. If you want the field to be read-only in Ketryx, set `"isEditableInKetryx": false` in the custom item fields configuration.

**Example:**

**1. Define the custom field in Custom item fields configuration:**

{
      "Custom Field Example": {
        "type": "SHORT_TEXT",
        "isEditableInKetryx": false,
        "syncToExternalSystem": true
      }
    }

This makes the field available and read-only in Ketryx, but not editable.

**2. Associate the field with the Requirement item type in Item fields:**

{
      "Requirement": {
        "addedFields": [
          {
            "kind": "CUSTOM",
            "name": "Custom Field Example"
          }
        ]
      }
    }

This ensures the field only appears for Requirement (REQ) items in Ketryx.

**3. Set the default value in Jira** for the "Custom Field Example" field on the Requirement screen. Ketryx will read this value for Requirement items only.

**Summary:**

By not including the field in **Extra field names**, you avoid the global behavior where the field would appear for all item types. For item-type-specific control, use **Custom item fields configuration** and **Item fields** instead. Please see the following for more information: [Custom item fields configuration](https://docs.ketryx.com/reference/advanced-settings#custom-item-fields-configuration), [Item fields](https://docs.ketryx.com/reference/advanced-settings#item-fields), [Extra field names](https://docs.ketryx.com/reference/advanced-settings#extra-field-names).