vocabularies

The role names of wheeled mobile carts that share one slot-profile (a wheeled multi-tier cart) and differ only by use: vegetable, kitchen, service, mop (janitorial), medical, utility. A growing vocabulary (L13). A janitorial mop/service trolley adds no exclusive slot over a kitchen trolley, so it is a value here, not a class (the fold discipline).

Answers the question: trolley type.