Does the definition of a Kanban board permit stacked lists? In other words, can an individual column contain multiple lists (rows). If not, is there another design similar to a Kanban board that does permit this?
These are typically called Kanban Swimlanes.
Swimlanes are used to categorize tasks so users can more easily find the task they are looking for:
- by customer or project
- by team
- by priority (sometimes called "classes of service"). Example: the "expedite" swimlane in the screenshot by Siddarth Maran.