When knives of different types are put up together as a set for retail sale, GRI 3(b) applies: the set is classified by the component that gives it its essential character. For most consumer knife block sets, the kitchen or chef's knives typically confer essential character, but the composition of the specific set must be evaluated. Heading 8211.10 is the dedicated provision for such assorted sets, avoiding the need to split the entry across multiple subheadings.

Each knife in the set must be individually marked with its country of origin under US marking rules (19 CFR Part 134), unless the marking is on the set's retail packaging in a manner that is clearly visible and not easily removed. If knives within a single set originate from different countries, each piece must reflect its own origin — a common compliance issue for sets assembled from components sourced across multiple countries.