You can modify custom data types (rename, add or delete values, and so on) before or after the custom data type is being used in a custom field.
What you should know
The following limitations apply when modifying custom data types:
- You cannot delete a value if it is being used as the default value for a custom field.
- You cannot change the standard data type on which the custom data type is based.
- Open the System task, and click the General settings view.
- Click the Custom fields page, and click the Custom data types tab.
- Select the data type, click Edit the item (), and follow the wizard.