Trackers and priorities
The kinds of ticket people can raise, and the priorities they can carry.
Administration → Trackers & priorities
Two independent lists live on this tab: the ticket types (trackers) and the priority levels. Impact × Urgency has its own tab, since it derives a Priority rather than managing either list directly.
A tracker is a ticket type (Incident, Service Request, etc.) offered when creating a ticket. Restore defaults adds back any built-in tracker that was deleted, leaving renamed or recoloured ones alone.
A tracker appears in the create form only if it is one of the built-in ticket types — Support Ticket, Incident, Service Request, Change Request, Problem — or was created with Behaves like set to one of them, which also opts it into that type's SLA, Problem Management and CAB rules. Anything else is saved but shows a "Not used in creation" badge here.