After a user has submitted a print request, you can change its priority in the print server's queue by:
Putting any print request on hold if it has not finished printing. Putting a request on hold stops it, if it is currently printing, and keeps it from printing until you resume printing it. Other print requests go ahead of the on-hold request.
Moving any print request to the head of the queue, where it will be the next job eligible for printing. If you want a job to start printing immediately, you can interrupt the job that is currently printing by putting it on hold.
Changing the priority of a job still waiting to be printed, moving it in the queue so it is ahead of lower priority requests and behind requests at the same level or at a higher priority.