'Priority'Escalation is the process whereby the Priority of a Ticket is raised (or, in rare cases, lowered) over time. This is done in RT to make sure that tickets do not stay forever without ever being handled.
Escalation is not done by default inside RT. An external program should be called once a day if one wants to make use of PriorityEscalation. PriorityEscalation can be configured on a queue-by-queue basis using the standard tools that come with the RT installation.
See also: ConfigureEscalation