0802.91 - Pine nuts, in shell:

This HTS subheading, 0802.91, specifically covers pine nuts that are still contained within their shells. This classification applies to pine nuts in their natural state, prior to any shelling or peeling process. The scope is limited to the intact product as harvested and prepared for trade, excluding any processed forms.

This category is distinguished from its sibling categories by the presence of the shell. HTS 0802.92 pertains exclusively to pine nuts that have been shelled, meaning the edible kernel is separated from its outer casing. Similarly, 0802.99 covers other types of nuts not specifically listed, but this subheading is reserved for pine nuts in their un-shelled form.

Within this subheading, further distinctions are made based on the specific type of pine nut. Subcategory 0802.91.10.00 is for "Pignolia" pine nuts, a widely recognized variety. The residual category, 0802.91.90.00, is for any other types of pine nuts that are imported in their shells and do not fall under the "Pignolia" designation.