A user can reference a custom list in "Custom Fields" within NetSuite. Custom lists are used to create predefined lists of values that can be selected in custom fields across various record types. This functionality allows for consistent data entry and reporting by ensuring that users select from a standard set of options rather than entering free-form data. Custom lists are highly versatile and can be applied to various custom fields, making them an essential tool for tailoring NetSuite to meet specific business requirements and data management practices. By linking a custom list to a custom field, administrators can enforce data integrity and streamline processes within the NetSuite environment.References: NetSuite Help Center, Customization Guide.