I ran into the same issue. After sending the situation up the reporting chain I received permission to require supervisor contact information on the borrower's agreement, see attached. Some would be flippant about providing that information, so I would remind them that the materials are government property and to come back with the required information.   I also started cc'ing the supervisor on the second email reminder if necessary.  I keep track of all reminders, etc. on the spreadsheet I use for circulation. 

/r,

Virginia