The barcode number on the back of your Princeton University ID card is required for most library services. It is a 14-digit number that begins with 22101. You should always enter it without any spaces. (Note that the barcode is called the Patron ID in the Borrow Direct system.) If you have a new Princeton University ID card, your barcode will need to be activated by staff at the circulation desk in Firestone or any branch library.
Bibliographic management software
Besides Firestone Library, the Princeton University Library system includes 14 separate discipline-specific libraries, each of which provides specialized reference and other services. For more information, see http://libweb.princeton.edu/libraries/libraries.php