Code 0303420000 is the parent-level 10-digit line that predates the introduction of the whole-fish (0303420020) and NESOI (0303420060) breakouts. In current US practice, importers should classify to the more specific lines based on the fish's dressed condition. The general code may still appear in legacy systems or statistical databases but should not be used for active entry filings where a more specific line applies.

Yes — if a shipment contains frozen yellowfin tuna livers or roes alongside whole or dressed fish, the livers and roes must be classified separately under the appropriate heading (typically heading 0303 or 0302 depending on condition), since they are explicitly excluded from this line. Mixed shipments should be invoiced with separate line items and weights for each component to facilitate accurate classification.