PWG PSI reference schema Copyright 2002, IEEE Industry Standards and Technology Organization/Printer Working Group. All rights reserved The reference element contains a reference to a document (PDL file, Word file, ...) at a particular location. The reference also contains the method by the which the document must be acquired (URL, ftp, ...). The attributes of the reference element are defined to be the same as those defined in the Bluetooth Basic Printing Profile (label, ip_addr, time). The attributes of the URL element are defined to have the same semantic meaning as those defined in the Bluetooth Basic Printing Profile (use_proxy, use_service, on401, on407, cookie, key) specified using the Universal Naming Convention