These three words help us to navigate the arcane world of customs codes, which do in fact follow logical rules. The underlying structure is called the Harmonised System. This is made up of groups of traded commodities, referred to as chapters which add up collectively as a schedule. Merchandise is listed in the order animal, vegetable and mineral.
The opening chapters cover live animals, followed by carcases and meat, moving on to animal products. Animals are followed by fish. Plants come next and are similarly classified in the order of seeds, then plants followed by retail fruit and vegetables.
A guide to the detail of customs classifications is in preparations and will be downloadable from this page in the coming weeks.