Print jobs received at a printer are assigned a reference which is incorporated as a representation of the reference in the printed print job. When the user recovers the printjob, the part of said print job incorporating said representation of said reference. is scanned back into the printer, which is then able to read the representation. By monitoring the time intervening between the printing of the print job and the scanning of the part of the print job incorporating the representation, the system is able to monitor the delay, and in a case where this exceeds a threshold to notify the user accordingly.