Operates on Service Orders, shown in the Zuper client app as "Work Order" (in every industry). Work Orders share the exact same underlying schema and endpoints as Purchase Orders / Material Orders; they're distinguished only by the purchase_order_type field (SERVICE_ORDER here) and the /service_orders route prefix. A UID belonging to the other module (e.g. a Work Order UID fetched via /purchase_orders/:uid) returns 404.