'Not elsewhere specified' means this heading is a catch-all for semimanufactured PGM forms that are not captured by a more specific provision. Importers should first check whether their product — for example, a platinum tube or palladium rod — has a dedicated HTS subheading before defaulting to this residual category. Working with a licensed customs broker and providing a full technical specification sheet is the recommended approach.

Palladium and palladium-alloy foils or membranes in their intermediate, unassembled form are generally considered semimanufactured and would fall here. Once the foil is assembled into a finished membrane module or reactor component, classification shifts to the finished article heading. The line between semimanufactured and finished article depends on the degree of fabrication and whether the item is ready for direct end use.