This line should only be used when the species genuinely cannot be determined from available documentation. In practice, most commercial flatfish fillet shipments identify the species on the invoice or catch certificate, which directs classification to the appropriate species-specific line. Using this aggregate line for identifiable species may trigger CBP inquiry or post-entry audit.

Yes. Flatfish fillets from China may be subject to Section 301 tariffs in addition to the base MFN duty, making origin documentation critical for landed-cost calculations. Importers sourcing from multiple origins should verify the applicable tariff treatment for each country with a licensed customs broker before committing to pricing.