Log System Notes For Custom Fields
Enable to create system notes during the import of data from custom fields. The option is disabled by default. Disabling system notes for custom fields improves performance and is preferred for imports that add data.
The option is available in a box on the step two Import Options page of the Import Assistant, when you expand the Advanced Options section.
System-generated notes are used in NetSuite to track changes to a record, including what action was taken, when the record was modified, and the user who is responsible for the change. These notes are important for maintaining a complete audit trail. If you turn off system-generated notes for custom fields, specific changes related to custom fields within the imported record are not recorded in NetSuite, although all changes for standard fields are logged as usual. If a custom field contains sensitive information that is critical for audit purposes, you should not disable system-generated notes. For more information about system notes, see System Notes Overview.