A locked print job requires you to enter a pass code at the printer in order for the document to begin printing. This can be handy in several scenarios:
You don't want your print job to end up in someone else's print pile.
You don't want others to see your document(s).
There are two ways to lock your print jobs. You can lock all of your jobs by default or you can do it on a per-job basis.
Lock a Single Print Job
In the print dialog, select your printer and choose Printer Properties, or Printer Preferences (it may vary from application to application).
Change the Job Type dropdown menu from Normal Print to Locked Print.
Click the Details button.
Set the User ID to your first name. This will help you find your print at the printer.
Set the Password to up to 8 numbers. This will be the code you enter to unlock your job at the printer.