Product transport declaration: Stores public transport declarations, such as batteries, hazardous materials, creams, liquids, or powders. import_information.product_transport_declaration
Trade item description: Stores a precise product description that describes specific attributes of the product for customs and import. import_information.trade_item_description
I would expect the transport declaration to come into play when buying shipping labels (for example not allowing air methods for batteries during checkout), but I don't actually know if or how it's implemented. I am not sure what purpose the trade item description would serve, maybe something included in a customs form generation?
Does anyone know if there is further documentation on how/when these particular standard metafields are utilized?